Since I cannot load my last configuration (at least I don't know how to get to the menu's) I'll have to reinstall. BTW I couldn't find a list of default hotkeys or keyboard shortcuts.
I'm not sure what would have caused it, but if you click the icon in the top-left corner of the window, you can get to Customize, and from there turn your toolbars back on.
Weird, indeed. I had a similar issue whereby some of my columns disappeared. A restart of Windows 10 fixed it, so reconfiguring your setup shouldn't be necessary.
People have had a lot of strange issues with Windows Defender lately, with it blocking Opus's access to files but not informing the user in any way. If you're using Defender and that was happening with your config files then it would explain why things are blank.
It's also possible something has corrupted them while or after they were written. (It shouldn't be possible for Opus alone to corrupt them, as we write them to a temporary file first, then rename it into place. But there have been cases where something else did.)
If you're using Windows Defender, it may help to whitelist Opus in all of its different areas: Realtime scanner, protected folders, privacy guard. The latter two in particular seem to make Defender arbitrarily block access to certain folders and files containing certain strings, without telling you what's happening, which means things break and you don't know why.
I rebooted windows 10 = no change. So I simply uninstalled and reinstalled, reloaded my last configuration and I was back in business. I have Windows Defender as off as I can make it (I'm using eSet).
I've been using dopus since ...... I think V8 and this is only the 2nd time I can recall for something to go haywire, so not bad.
I mostly wanted to let you know what happened in the event others have experienced the same.
BTW I was not restoring or making any backups, nothing going on that should even remotely cause a file corruption.