Resolution
This resolution can be applied if it is necessary to use .php, .asp, etc., applications on the domain.
First, make sure that this extension is allowed in IIS and for the domain.
In Plesk Control Panel, create a virtual directory for custom error document files: Domains, domain.name, Web Directories, AddNewVirtualDirectory (This directory will be created on the server in %plesk_vhosts%\domain.name\httpdocs\.)
Create a new file (script that will be run on this error):
Domains, File Manager, httpdocs, Created Virtual Directory, Add new File
Choose created file to be processed for the needed error:
Domains, domain.name, Web Directories, Error Documents, needed error, Location
The error needs to be specified in the following manner:
Type: URI
Location: /Created_Virtual_Directory/file.name
Note: Do not create custom files in the %plesk_vhosts%\domain.name\error_docs\ directory. If you do, they will not be processed because %plesk_vhosts%\domain.name\httpdocs\ is used as a home directory for custom files.
C:\Windows\System32\inetsrv>appcmd.exe set config -section:system.webServer/httpErrors /allowAbsolutePathsWhenDelegated:true