"Access denied for user ''@'localhost' to database 'forge" appears randomly
Try php artisan clear:cache
to clear your cache and re-configure your cache php artisan config:cache
it might works for you .
PLEASE RUN THIS COMMAND
php artisan cache:clear
THEN
php artisan config:cache
This seems to hold most of the answers : Laravel 5.2 not reading env file
Remember to not to edit your core files as one of the users said. Just do the safe checks, clear cache, should work.
Hope it helps.
As a workaround you can add to your DB forge account with all privileges.