Unable to remove a domain in Plesk Onyx 17.8 for Windows:
PLESK_ERROR: Internal error ;-P
ERROR: Error: Call to undefined method PHostingManager_IIS::_removeTomcatService() (IIS.php:1415)
Before Plesk was upgraded to Onyx 17.8, the fix from the article Web Deploy publishing fails: ERROR_USER_UNAUTHORIZED was applied on the server.
In Plesk Onyx 17.8, the Tomcat support was dropped, but the patched file
%plesk_dir%admin\plib\PHostingManager\IIS.php is still from Onyx 17.0 or 17.5.
Connect to the server using RDP.
Download the correct file using the URL https://support.plesk.com/hc/en-us/article_attachments/360006379793/IIS.php.
Put the downloaded file in the directory
%plesk_dir%admin\plib\PHostingManager\with replacing already existing file.