PM 866 controller communication issue
The log indicate problems with the networking, or networking hardware.
However, the below drew my attention
I 2019-12-01 19:18:57.092 Network Interface 172.16.4.151 (255.255.252.0 ) : 00-00-23-0d-9e-54
I 2019-12-01 19:18:57.097 Network Interface 172.17.4.151 (255.255.252.0 ) : 00-00-23-0d-9e-55
I 2019-12-01 19:18:57.102 Backup Interface 172.16.6.151 (255.255.252.0 ) (default rule)
I 2019-12-01 19:18:57.103 Backup Interface 172.17.4.151 (255.255.252.0 ) (explicit set)
The backup controller's secondary Ethernet interface setting is wrong; instead of using default rule (which adds 0.0.2.0 to the primary controller's counterpart) it has been manually set to the same address as the primary controller's secondary address. A manual setting is OK, but must be routable and not make conflict with any other address.
Please correct this conflict (serial cable, IPConfig.exe, controller reset, set Backup Interface --> Secondary --> Use Default Rule).
Then please download the application to the controller again and check the controller log once more.