Hello,
I have found a few bugs using PVS-Studio analyzer. PVS-Studio is a static code analyzer for C, C++ and C#: https://www.viva64.com/en/pvs-studio/

Analyzer warnings:

• V3010 The return value of function 'Reverse' is required to be utilized. PersistentFSMBase.cs 511
  A link to the source code.
• V3010 The return value of function 'Reverse' is required to be utilized. PersistentFSMBase.cs 532
  A link to the source code.
• V3095 The 'youngerData.Oldest' object was used before it was verified against null. Check lines: 711, 712. ClusterSingletonManager.cs 711
  A link to the source code.
• V3095 The 'becomingOldest.PreviousOldest' object was used before it was verified against null. Check lines: 850, 851. ClusterSingletonManager.cs 850
  A link to the source code.

In addition, I suggest having a look at the emails, sent from @pvs-studio.com.

Best regards,
Sergey Vasiliev