Do you have the wallet seed or a backup of the wallet? This should have been my first question.

EDIT: do you make backups of your pc at all? You really should. Things can get corrupted. Programs can crash, cosmic rays can corrupt your data etc.. But in your case this may be too late already 

Assuming you haven't upgraded your electrum client like nerioseole asked:


This command will rename your configuration file to to configuration.bak so that Electrum will make a new configuration:


Next you will want to open Electrum.

It will ask you to import or create a wallet. The importing option only allows for wallet recovery using the seed. Since we want to import your old wallet from a file we just go ahead and create a new wallet so that we can get past this screen. Go ahead and make a new wallet.

Once you have Electrum open like normal, select File, click Open wallet. Your wallet should be there. Select it. Click ok and you should have your wallet back.

If that didn't work for you let me know


Handy hint. Files starting with . are considered hidden. Push ctrl + H to show them.