Subscription mode. Catastrophic failure error -> blocked Subscribe/Unsubscribe - by: Andriy

Hello,

I receive a lot of "Catastrophic failure" errors on ItemChanged event handler.
I don't know what it means and how I can handle it.
Can you provide information about this error: when it is risen and how I can fix it.
I don't know if it's connected or not, but I get this error when the OPC DA server periodically crashes.
What is worse, my application after that cannot reconnect to the OPC server when it is up and running

QuickOpc version=5.54.1115

Thank you