Up-scaling from what to what?
What do your Crash logs tell you?
Any upscaling. I have tried on large and small images, used different upscaling algoritms, tried using percentage and pixels. Always crashes on submit. Crash logs are sent to adobe. I do not know where to see them.
Open Console and then, if the toolbar is not visible, choose *View > Show Toolbar*.
Press the Logs button and then navigate to ~/Library/Logs > CrashReporter or /Library/Logs > Crash Reporter and choose the Photoshop report.