Version 1.6.7 doesn't want to close and hang. Windows detect unresponsive software and close it with a warning window.
Only open ACCR and select one entry in session is enough to make it hang.
Open ACCR and close it without selecting anything makes it close correctly.
correct close log:
[00000008] 2020-07-25 13:00:20 INFO FileUtils.OpenBroadcastConnectionDetails : Broadcast/UDP configured on port [9000]
[00000001] 2020-07-25 13:00:27 INFO ACCResults.formCloseRequested : *** Form close requested ***
[00000005] 2020-07-25 13:00:27 INFO ARCProcessStats.MonitorMemory : *** Memory monitor closing ***
[00000008] 2020-07-25 13:00:27 DEBUG ARCSharedMemoryMonitor..ctor : Stop event received
[00000006] 2020-07-25 13:00:27 INFO DBWriterTask.ProcessDbRequest : Stop event received
[00000008] 2020-07-25 13:00:27 INFO ARCSharedMemoryMonitor..ctor : *** Shared Memory monitor closing ***
[00000006] 2020-07-25 13:00:27 INFO DBWriterTask.ProcessDbRequests : *** DB Writer task closing ***
[00000001] 2020-07-25 13:00:27 INFO ACCResults.formCloseRequested : Process statistics process has closed
[00000001] 2020-07-25 13:00:27 INFO ACCResults.formCloseRequested : Shared memory/Broadcast process has closed
[00000001] 2020-07-25 13:00:27 INFO ACCResults.formCloseRequested : DB Writer process has closed
[00000001] 2020-07-25 13:00:27 INFO ResultsDB.Close : Closing DB connection
incorrect one:
[00000008] 2020-07-25 13:00:32 INFO FileUtils.OpenBroadcastConnectionDetails : Broadcast/UDP configured on port [9000]
[00000001] 2020-07-25 13:00:45 INFO ACCResults.formCloseRequested : *** Form close requested ***
edit :
current installed .NetFramework (latest)