I tried to log in with a friend’s accoud, she wont play anymore so I wanted to get some of her items, but she had founders pack, and when I tried to open the game, it downloaded a small update and then proceeded to, what seems to me, re-download the entire game, or a very big update, and it crashed at 52%, now its back at 1% and moving suuuper slowly.
What can I do to revert the client to where I had it prior trying to log in with ny friend’s account? 
Thanks!
I haven’t played in forever but there’s something tied into the founder’s packs being “DLC” to the game and patching. It caused me problems a long time ago and might be a cause here. You might have to uncheck them under the DLC or completely reinstall the game from scratch then not login that account.
1.) Open Steam
2.) Right click ToS
3.) Click on 'Properties’
4.) Go to ‘Local Files’ tab
5.) On Local Files tab, keep note of what "Current Build ID: #"
6.) While on the same tab Click 'Browse Local Files’
7 .)You’re now shown the ToS game folders
8.) Go to 'Releases’
9.) Open “release.revision.txt”, number in txt file must be same with listed Current Build ID on Steam, if not, change to Current Build ID’s number
10.) Now go back to Steam’s ‘ToS Properties Local Files tab’, Click ‘Verify Integrity of Game Cache’
Sit back wait for file verifying to finish, after that Steam will auto download patch update/get missing files of ToS, once it finishes downloading start up ToS.
Hope this helps