How to fix metamask white screen of death in Firefox in Linux

I encountered an issue where metamask screen in firefox, this is what I did to fix it:

Go to:

/home/USERNAME/.mozilla/firefox/STRING.dev-edition-default/storage/default/moz-extension+++UUID^userContextId=NUMBER/idb/

That folder should have another one inside in the shape of:

UNKNOWNSTRING-eengsairo.files

Where:

• USERNAME: your username
• STRING: a particular string in your system, also in your case it might me dev edition.
• UUID: The Internal UUID of the metamask extension, find it by pasting about:debugging#addons in your address bar, it's on the metamask extension, labeled as Internal UUID.
• NUMBER: Some number I don't know where it comes from, you might have several, find one where you can find the folder ending in eengsairo.files.
• UNKNOWNSTRING: Same as above, no idea where this comes from.

There's an sqlite database there, you can open it with an SQLlite browser. On Browse Data tab, in the file table, there is only one row (in my case), where the id is a number you should remember, let's call it MAGICNUMBER.

Inside UNKNOWNSTRING-eengsairo.files, there should be at least a file with a number as it's name, copy the highest numbered file into a new file called MAGICNUMBER:

cp OLDFILENAME MAGICNUMBER

And that's it.

Use this solution at your own risk, remember to backup the files you'll need, it's a simple cp file fileBackUp away from potentially losing funds.

This solution is based on this answer in metamask forum.