I can't help with your current issue, but in the future, you could consider backing up your Google Docs using Insync. It can automatically convert and store you

I can't help with your current issue, but in the future, you could consider backing up your Google Docs using Insync. It can automatically convert and store your Google Docs as Office or OpenDocument files. Insync has a few quirks, but it usually does the job and is very affordable. (I am not affiliated with Insync.)