Problem

B2Bx server task crashes with following error in Integrator trace log and in the UI Integrator shows no connection because of this.

ERROR :20150814:15.38.08.67:r4edi(b2bx_server):KSSystemNode:132:FORCED STOP: Reason GetSystemNodeCandidate failed: UNSERIALIZE: string and destination variable does not match

Resolution

This error could come if the content of systemnode.dat file are invalid. Check this file under B2BI_SHARED_DATA}/kernelserver/systemnode directory.
Take a backup of this file and then delete it and on restart of Interchange it should get recreated.