We have been using a Friends Only server since Alpha 20 was released, and have had Drones following us around since we first encountered them.
About 3 in-game days into 20.4, 3 of us got hit with this issue and it was right before a Blood Moon was about to start. We tried server restarts and other debugging steps which ended up not working until we encountered this thread.
One of us stayed safe by putting the drone away as soon as we learned that it was a probable cause.
Another managed to avoid the issue for awhile by running away from their spawn point after recovering from this crash. Which managed to prevent the Drone from waking up and following them around causing a crash. After the blood moon, they walked over to the drone, which then activated. They emptied it's inventory, put the drone into their inventory, and then got this crash. After a logout and log in, they seemed fine, and had the drone on their belt.
Another followed Backslash2099's advise and that resulted in a .ttp that went from a bit over 2,000 KB to 30 KB after using a single player world to sanitize it. There was some strangeness with their inventory, but it seemed to work out.
Another followed those same steps, but got error messages about downloading and modifying data, and each time they loaded that profile, they got a level 1 character at a starting point, with a 10 KB .ttp file. We ended up using a backup of their profile from earlier in the day. They lost 3 in-game days worth of progression, but that's better than starting over from scratch.
When the issue was hitting us, we couldn't go longer than 30 seconds logged in before the console error would show up, and then be in a private session type thing where the other players would be stationary, and we couldn't interact with world objects.
After our various recovery steps and preventions, we managed to finish the Blood Moon (After using some settime commands on the server to delay it a bit while we debugged) and stay connected after the looting and rebuilding afterwards.
The 20.3 backup files for all 4 of our player profiles have about 2,000 KB .ttp files.
After we shut down the server post blood moon, the one that had a restore, and then shoved the drone into a storage box is at 30 KB.
The one with a successful singe-player sanitize is at 62 KB.
The one who avoided it by putting a drone in a box before getting the error is at 1,777 KB.
The one who ran from the drone, then went back for it is at 2,045 KB with the drone still in their inventory. This one knows to watch out and stash the drone somewhere safe next time we launch the server.