We heard from several customers that the newest Windows 10 Update makes QuarkXPress 9 lose its activation, though in the past QuarkXPress 9 ran fine on Windows 10.
As QuarkXPress 9 was never supported on Windows 10, we have no information why this happens or how to prevent that.
Remember, Microsoft typically pushes updates to Windows 10 automatically and silently and it is hard to turn silent automatic updates off.
And Microsoft announced that they will continue to call Windows "Windows 10", though since 2015 they have released updates to Windows 10 that normally would have been called major upgrades.
So when this automatic silent update of Windows 10 happens, without noticing you'll have a new version of Windows 10, and this is probably what causes this to appear as "suddenly fail".
Only two solutions we can offer:
- Please revert to Windows 7 or 8.0, as QuarkXPress 9 was supported on these versions of Windows: viewtopic.php?f=14&t=4608
- Please upgrade to a version of QuarkXPress that supports Windows 10, so QuarkXPress 2015 or higher: viewtopic.php?f=8&t=27713
P.S.: This could also happen to older versions of QuarkXPress, like version 8 or 7. Again, we have no info here, as also these versions have never been supported on Windows 10.