Description
Due to a problem in the Quartus® Prime software Pro and Standard edition version 16.1 Update 2 and earlier, you may see the tool hangs at the fitter stage ending with a message "The Fitter is using Advanced Physical Optimization". This problem occurs if you have the maximum processors allowed set to auto.
Resolution
To work around this problem, change the auto processors to a value with:
Assignments -> settings -> Compilation process settings -> Maximum processors allowed = <a value where your computer can support>
This problem is scheduled to be fixed in a future release of the Quartus Prime software.