If the export does result in an audio file, however long it takes, then I don’t think you have a problem. Without knowing what you’ve got loaded in these projects, I would guess that some elements - 3rd party plug-ins maybe - are taking a bit of time for Cubase to calculate, but it works it out eventually. Not all 3rd party plug-ins are equally well implemented. And if you have 32-bit plug-ins on a 64-bit system this introduces another area of uncertainty.
If this is becoming a significant problem, I would suggest that you render in place (print) tracks before you export, perhaps even batch export each track to a new project, just to keep prints (stems) away from working audio. Lots of people do this before they embark on the final mix, anyway, as it takes strain off the system. Finalizing your work as new audio tracks is not bad practice in general, if nothing else just to protect yourself against future upgrades. And it means that life is a lot easier if you want to take your project to another system to work on elsewhere.
I’m sure there’s more to add to this but that’s my two cents…
Try to do a clean install of your graphics drivers. This is the only thing I have ever seen mentioned as fixing this bug that pops up now and again though only mentioned by one guy so might not work for you.
NB: If you tick update display in the export dialogue the cursor should move along the timeline to show progress even if the export meter is frozen
Yes, it does as you say on the timeline if I tick that. Not seen the problem before myself until this week, it just threw me seeing it. It does export the audio. Not sure why it’s just started doing it.
I did as you said, clean install of gfx drivers but it didn’t change anything… sadly