I accidentally deleted a deck that I needed. I tried exporting a deck from a previous backup and when it exported, it “came out” as three files. The names are:
MCAT 2.apkg
MCAT.anki2
MCAT2.media
I tried to re-import just the apkg file, which did not work and gave me the error “This file does not appear to be a valid .apkg file. If you’re getting this error from a file downloaded from AnkiWeb, chances are that your download failed. Please try again, and if the problem persists, please try again with a different browser.”
Thats what I tried, multiple times. I would open a previous automatic backup that contained the deleted deck by switching profiles and then downloading the deck to my desktop. When I did this, instead of giving me one .apkg file, it gave me three file types mentioned earlier. Importing them back into anki did not work.
I tried disabling all add ons upon opening anki and checking the database (Tools > Check database), as this was a recommendation from one of the error types I received.