Use FFYL if you don't have any "Spark keys" errors
If you have - then use FFYLOF

Where to extract? 

Example Directory:
 E:\SteamLibrary\steamapps\common\Borderlands 2\Binaries 

How to use? 
1) Open Console
2) Type: exec FFYL 
3) If you don't see any "Spark Keys" errors, they you are fine and you can play
4) If you see "Spark keys" errors, then type: exec FFYLOF