Prom Module "Conformance Checking of DPN" throws impossible exception

I took the XES-log below, applied the Alpha-Algorithm with standard settings to it and then module
"Conformance Checking of DPN" with standard settings on the Petrinet and the log. In this last step I corrected the default mapping to map D+complete to D and put End as a final marking.

I then got this:
"Failed to compute the empty trace alignment, Nested Exception: org.processmining.plugins.balancedconformance.controlflow.UnreliableControlFlowAlignmentException: Unreliable result after visiting 1 states, queueing 1 states. 0 data alignments cached, 0 cache hits for trace [], Reason: IMPOSSIBLE"

Is this a bug or is it a hidden message that something with my log or my Petrinet is wrong?







<?xml version="1.0" encoding="UTF-8" ?>
<!-- This file has been generated with the OpenXES library. It conforms -->
<!-- to the XML serialization of the XES standard for log storage and -->
<!-- management. -->
<!-- XES standard version: 1.0 -->
<!-- OpenXES library version: 1.0RC7 -->
<!-- OpenXES is available from http://www.openxes.org/ -->
<log xes.version="1.0" xes.features="nested-attributes" openxes.version="1.0RC7">
    <global scope="trace">
        <string key="concept:name" value="UNKNOWN"/>
    </global>
    <global scope="event">
        <date key="time:timestamp" value="1970-01-01T00:00:00.000+01:00"/>
        <string key="concept:name" value="UNKNOWN"/>
        <string key="lifecycle:transition" value="UNKNOWN"/>
        <string key="concept:instance" value="UNKNOWN"/>
    </global>
    <classifier name="Activity classifier" keys="concept:instance concept:name lifecycle:transition"/>
    <string key="concept:name" value="Merged Log"/>
    <trace>
        <string key="concept:name" value="405"/>
        <event>
            <int key="x" value="1"/>
            <string key="lifecycle:instance" value="405.1"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:35:07.122+01:00"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="lifecycle:instance" value="405.3"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:36:25.595+01:00"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="lifecycle:instance" value="405.2"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:36:32.229+01:00"/>
        </event>
        <event>
            <string key="lifecycle:instance" value="405.4"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:37:52.355+01:00"/>
            <boolean key="again" value="false"/>
        </event>
    </trace>
    <trace>
        <string key="concept:name" value="406"/>
        <event>
            <int key="x" value="1"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.1"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:35:30.932+01:00"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.3"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:36:46.737+01:00"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.2"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:36:51.404+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.4"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:38:01.506+01:00"/>
            <boolean key="again" value="true"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.5"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:39:04.815+01:00"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.7"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:39:46.103+01:00"/>
        </event>
        <event>
            <int key="x" value="1"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.6"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:39:49.280+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="406.8"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:40:39.098+01:00"/>
            <boolean key="again" value="false"/>
        </event>
    </trace>
    <trace>
        <string key="concept:name" value="407"/>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.1"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:35:41.210+01:00"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.3"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:36:58.059+01:00"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.2"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:37:02.094+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.4"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:38:09.548+01:00"/>
            <boolean key="again" value="true"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.5"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:39:11.160+01:00"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.6"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:39:56.812+01:00"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.7"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:40:01.049+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.8"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:40:44.395+01:00"/>
            <boolean key="again" value="true"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.9"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:41:03.936+01:00"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.11"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:41:28.034+01:00"/>
        </event>
        <event>
            <int key="x" value="2"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.10"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:41:31.392+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="407.12"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:42:13.778+01:00"/>
            <boolean key="again" value="false"/>
        </event>
    </trace>
    <trace>
        <string key="concept:name" value="408"/>
        <event>
            <int key="x" value="3"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="408.1"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:35:49.567+01:00"/>
        </event>
        <event>
            <int key="x" value="3"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="408.3"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:37:10.022+01:00"/>
        </event>
        <event>
            <int key="x" value="3"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="408.2"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:37:14.802+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="408.4"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:38:26.713+01:00"/>
            <boolean key="again" value="false"/>
        </event>
    </trace>
    <trace>
        <string key="concept:name" value="409"/>
        <event>
            <int key="x" value="4"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.1"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:35:56.017+01:00"/>
        </event>
        <event>
            <int key="x" value="4"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.2"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:37:22.422+01:00"/>
        </event>
        <event>
            <int key="x" value="4"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.3"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:37:25.531+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.4"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:38:46.755+01:00"/>
            <boolean key="again" value="true"/>
        </event>
        <event>
            <int key="x" value="4"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.5"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:39:18.239+01:00"/>
        </event>
        <event>
            <int key="x" value="4"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.6"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:40:08.830+01:00"/>
        </event>
        <event>
            <int key="x" value="4"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.7"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:40:11.914+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="409.8"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:40:51.638+01:00"/>
            <boolean key="again" value="false"/>
        </event>
    </trace>
    <trace>
        <string key="concept:name" value="410"/>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.1"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:36:03.801+01:00"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.3"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:37:30.991+01:00"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.2"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:37:35.938+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.4"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:38:53.957+01:00"/>
            <boolean key="again" value="true"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.5"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:39:37.962+01:00"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.7"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:40:16.230+01:00"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.6"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:40:19.655+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.8"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:40:58.237+01:00"/>
            <boolean key="again" value="true"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.9"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="A"/>
            <date key="time:timestamp" value="2017-01-31T09:41:10.746+01:00"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.11"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="C"/>
            <date key="time:timestamp" value="2017-01-31T09:41:37.418+01:00"/>
        </event>
        <event>
            <int key="x" value="5"/>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.10"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="B"/>
            <date key="time:timestamp" value="2017-01-31T09:41:41.265+01:00"/>
        </event>
        <event>
            <string key="org:resource" value="PA-1d65ff97-7ae9-40cd-b59e-c2605b1b6a9b"/>
            <string key="lifecycle:instance" value="410.12"/>
            <string key="lifecycle:transition" value="complete"/>
            <string key="concept:name" value="D"/>
            <date key="time:timestamp" value="2017-01-31T09:42:19.323+01:00"/>
            <boolean key="again" value="false"/>
        </event>
    </trace>
</log>