What is the reason for the following error in file OPCUA32.txt? 
It happens at the closing the runtime

zenOn Version: 8.20 SP0 Build80611
Processor: x86
//-----------------------------------------------------
Exception code: C0000005 ACCESS_VIOLATION
Fault address:  004DF64A 01:000DE64A C:\Program Files (x86)\COPA-DATA\zenon 8.20\OPCUA32.exe


and in the log file there is also "RCP error" for the driver, which is the meaning?