Thanks for the confirmation. Please execute the command from my previous reply corresponding to your OS. If you get the same output as before then the main.css file is modified again. If you haven't done it manually, this will indicate that some other process does (possibly malicious). However, this must be further investigated by our team. I would suggest opening a ticket with Plesk support. To sign-in to support and open a ticket go to
If you got your license from a reseller, your reseller is responsible for providing support. They can escalate the request to our team on your behalf. If the reseller does not provide support, here is an alternative to get support directly from Plesk:
If you got your license from a reseller, your reseller is responsible for providing support. They can escalate the request to our team on your behalf. If the reseller does not provide support, here is an alternative to get support directly from Plesk: