Unable to access Excel file in iCloud

I have a very important Excel file I've built through the years. I store it in iCloud/Files in hopes that it would keep it protected. The past few days, I've been unable to open it. I also cannot seem to locate a version history within iCloud, every article/thread I find says to open the file, then view version history, however - that's useless if you can't open the file at all. Please tell me it's not gone!

[Re-Titled by Moderator]