Okay, after 3 months of mining during the last couple weeks rig has been freezing and the last line of the log file indicates:
GPU got incorrect temperature 511 ignore
Thoughts?
I got this error when one of the fans on an RX580 failed. I don't know how long it was running with one failed fan but when I noticed the failed fan the card was very very hot !
In that case, the temperature was so high that the card itself couldn't measure it and that's why you got GPU got incorrect temperature 511.
That's my guess.