I have updated TeXStudio and now, when I compile, all work without errors. But If I "compile and view" or simple "view" The answer is:
File 'path\paper.ps' does not exist
from GSview.
Till yesterday, I had not any kind of this problem. Today I add the command \hyphenation in the code, but TeXStudio and MiKTeX work fine and I have my PDF output without errors.
Best Answer
This topic is quite old, but I just had the same issue and found a solution. For some reason, an update changed the "Default Viewer" in Options > Configure TeXstudio > Build. I simply copied the line from the PDF Viewer command (for me txs:///view-pdf-internal --embedded). I have not encountered this with build and view, but if you do the script might have changed for ps viewer. For an embedded pdf : txs:///pdf-chain.
Hope it helps someone in the future.