I’m trying to recover my bitwarden account after I accidentally lost my master password. I remember the previous password from a few days ago and have time machine backups daily before that.
What is the best way I can restore the previous bitwarden instance and open it up, login with my previous master password?
I just lost access to my bitwarden password manager (reset master password, and saved it inside my PW manager… ugh). I was doing too many things at one time and didn’t realize what I did.
This is going to ruin my entire life. I have all of my banking, business, and personal life inside of this thing.
I didn’t have an emergency contact set up.
I did at one point have a ubikey but disabled it because it was a lot of trouble to use for every site, and program all day long.
I messaged support and they basically told me I’m out of luck. I am devastated.
I considered restoring my mac time machine backup and removing the internet access from it to try and restore my old bitwarden instance from yesterday and export all of my logins to a file.
I was able to replace the app itself with the version from yesterday but in doing so, it’s still logged out. I then replaced the bitwarden folder inside “application support” and that didn’t let me in because the application was logged out when I opened it.
Is there a way I can use time machine and the previous vault to accomplish this?
I don’t know what else to do. 
We have collected most all our knowledge on not being able to login to one’s vault into [Guide] "I can't login" - Some tips for login problems/issues. You might start there to see if there are any avenues you left open for yourself.
Only if you are able to restore an app/extension data folder from a backup that was taken while the corresponding app or extension was logged in. After restoring the folder, disconnect from the internet before opening the app or browser to check whether you are presented with an unlock prompt or a login form.
You should also try to remember whether you have ever logged in to Bitwarden on any other devices that you may still have access to. Again, it is critical to disconnect such devices from the internet before checking whether there are any Bitwarden apps or extensions that are still logged in (which could happen, if the Bitwarden app and/or browsers on an old device have not been accessed since you did the password change).
Other than that, you would have to recall (or otherwise find a copy of) the new master password.
P.S. I moved the post that you had made in an old Feature Request thread to the top of this topic.
It seems OP managed to restore the vault from a desktop client’s encrypted vault cache’s backup.
Just for the record, and for future reference: BitwardenDecrypt (what OP used to decrypt his vault’s cache) is a very nice python script. But I’ve done some experiments with it and a test account’s vault cache; and not always it was able to decrypt it for me.
Plus, that repo doesn’t seem to have had too much activity in the last months.
TLDR; Don’t rely blindly on this kind of tools and always keep your backups and emergency sheet up-to-date.