Time Machine hasn't backed up for a week. It says "There isn't enough space," and yet there is plenty.
I'm backing up to a Western Digital My Passport with 5 TB capacity and 4.81 TB free. Time Machine correctly reports there is 4.81 TB.
I have a 1 TB hard drive on my MBP running Catalina. If I click on the options for Time Machine it says: "Estimated size of full backup: 100.51 GB."
However, when I click on the red "information" "i" next to the Latest backup, it reports that it needs 50.21 PB (yes, PB) of space. What in the world? I already have things like