clWaitForEvents(): CL_UNKNOWN_ERROR

Hello all,
Can some one tell me why I am getting this error please [s]tatus [p]ause [b]ypass [c]heckpoint [q]uit => clWaitForEvents(): CL_UNKNOWN_ERROR
clEnqueueReadBuffer(): CL_OUT_OF_RESOURCES . Only happens on sha512 with wordlist and rules.
Time out patch installed and Nvidia driver up todate
Cheers Kev