I can't preview Excel-files anymore (Word works and Excel did before). I didn't change plugins-settings or anything else (I don't use it often and noticed it first in Beta 7).
Edit: Using legacy-preview works but wasn't activated and is not recommended. Also noticed, that Word-preview hides header and footer in non-legacy-plugin.
Do you get the same results in Explorer's viewer pane? This sounds like an Office issue rather than an Opus one. You may need to repair your Office installation.
Explorer shows "no preview available", also DO offers none (preview-handlers for Word, PP, etc. are available). I did a repair, but that changed nothing. Never had trouble before, any ideas?
Repairing Office and assigning filetypes back to it are my only ideas.
Best to ask on a forum of Office experts, since it's not Opus going wrong and they may have better knowledge than anyone here.
If someone has same issue, here's the fix: https://support.microsoft.com/en-us/kb/3114374 (choose for x86 or x64)