A blocking read is just that. A driver that blocks waiting for data. If the data does not come – gridlock.
I’m not sure its the driver, it could be soomething else. Is it possible you have a Tcl proc that gets in an infinate loop?
Did you turn up EO? What was the last thing the engine was doing when it blocked?
All sorts of possibilities. Is it always 1 process that hangs? Try moving some of the threads to other processes and see if you can isolate it to a thread. You could also place some Debug statements so you can see whta was happening when it blocked
Hard to debug from here.