I am not a native English speaker, so I used translation. Please excuse any awkward phrasing. I previously updated my Firefox to version 150, but my tabs kept crashing roughly every 5 minutes. To solve this, I tried installing the Firefox ESR version. However, my profile had already been upgraded to the new version format, so ESR could not read my data. I then reinstalled version 150, but now I'm having profile issues again. I can access and launch my old profile through about:profiles, but I can't seem to save it directly as the default profile. I don't want to have to repeat this process every time I restart the browser. Is there a way to transfer all my data (bookmarks, saved passwords, add-ons, settings, etc.) to a new profile that works with the current version? Or, can I downgrade my profile so that ESR can read it? I have tried copying the files from %APPDATA%\Mozilla\Firefox\Profiles, but it didn't work after many attempts. Please help me. I really don't want to set everything up from scratch again. Thank you!