update plugin

It sounds like there was an error during the update (perhaps a timeout issue, or memory limit reached – you would have to review your website error log file for an exact cause).

If the update didn’t complete correctly you may have been stuck in “maintenance mode”. Here’s a guide on how to manually exit this mode.

If the problem persists you may have to update the software via the FTP method. This guide discusses installing via FTP. Just ensure you delete the existing gravity-forms-pdf-extended directory before following the guide instructions.