SymptomsWhen attempting to log into Plesk Panel, the following message is displayed:
The file filename.php is part of Plesk distribution. It cannot be run outside of Plesk environment.
CauseA *The .php file cannot be decrypted by the Plesk engine. This could have been caused by one of the following two issues:
1. The Plesk key installed is invalid. This means that you could have installed a Plesk key for Linux, not for Windows or visa versa.
2. The Plesk php environment is corrupted.
ResolutionTo fix the first cause you need to complete the following steps:
1. Close your browser, or make sure that your browser does not show cached web pages.
2. Stop the Plesk Control Panel Service.
3. Remove all files from within %plesk_dir%PrivateTemp directory. Reset current Plesk to the default PLSK.00000000.0000. You can do this by using defpkey.reg attached to this article.
4. Start the Plesk Control Panel Service.
5. Re-upload the valid Plesk key straight from Plesk Panel. You can upload the PLSK.XXXXXXXX.XXXX.exe key.
To fix the second cause you need to complete the following steps:
1. Switch Plesk web server to another provider.
If IIS is used as Plesk web server switch it to Apache:
%plesk_bin%\reconfigurator.exe --switch-plesk-web-server --new-provider=apache
If Apache is used as Plesk web server switch it to IIS:
%plesk_bin%\reconfigurator.exe --switch-plesk-web-server --new-provider=iis
Check if Plesk works correctly once these steps are completed. If the same error is displayed, the Plesk PHP files were corrupted. In this case, you need to run Plesk Repair in Add or Remove Programs.