Can't edit files

when ever i edit a line in any file i get this error with this err code 500
/ / / / / / / / /
Looks like something went wrong!

We track these errors automatically, but if the problem persists feel free to contact us. In the meantime, try refreshing.

and now i can’t even open edit page.

I think GitHub is experiencing some problems.

500 Internal Server Error Variations.
Try Reloading the Page
Clear Your Browser Cache
Check Your Server Logs
Error Establishing a Database Connection
Check Your Plugins and Themes
Reinstall WordPress Core
Permissions Error
PHP Memory Limit