Check the logs in the log folder. All powershell outputs are sent there so you can see what the error is that's repeating.
I have a gtx1080, and the mutlipoolmner never seems to finish 'benchmarking' , i see red error text show up in the powershell in between algos, but can't make it out. how long should it take? i havent gotten to the part where I can actaully mine yet