Kepware connection issue to Rockwell 1756-L72

[KV_11492436]

I've made a Kepware configuration for about 10 Rockwell plc's. But i have an error on one of them. All other 9 are working fine.
It is a 1756-L72 CPU where i have issues to connect with. We've a working connection to another PLC with the same configuration which is working fine.
I don't see an error message in the diagnostic list of Kepware. what is the best way to proceed with this to find a root cause and a solution?

[VladimirN]

Maybe the following discussion will be useful - "Integrating KepserverEX 6 with Rockwell Ethernet card in remote rack": https://community.ptc.com/t5/Kepware/Integrating-KepserverEX-6-with-Rockwell-Ethernet-card-in-remote/td-p/953718 

[KV_11492436 · Accepted solution]

This didn't help.

We made a connection to the webpage of the netwrok card. On that page we could see that the CPU power of the network card was on 100%.

Kepware is the first connection it starts to refuse if this is the case.

Lowering the load on the network card solved my problem.