I´m playing on my own server and everytime I attempt to open any Flux Network Item I´m kicked from the server with the message "A fatal error has occurred, this connection is terminated" I´ve installed the latest Versions from Flux Networks and Sonar Core for minecraft 1.10.2

Send a crash report and I'll see if I can help, but fyi 1.10.2 is no longer supported.

The problem is the game isn’t crashing. I‘m only kicked from the server and the server log says only Player lost connection

Do you have the debug.log? It should indicate the issue.

Ah okay, afraid without the log really not much I can recommend.

I dont have a Debug log for today neither in my .minecraft logs folder nor in my Server log folder

Ok but thanks for your help