Microsoft FrontPage extensions allow editing/managing a web site with Microsoft FrontPage, even on a Linux/Apache web server.

These extensions are notoriously fragile though, and will often stop working properly for a variety of reasons.

Fortunately the problems are usually easy to fix by "reinstalling" the extensions.

Plesk:
* Log in to Plesk at https://any_of_your_ips:8443/
* Click Domains
* Click the domain of the site exhibiting the problem
* Click "Setup"
* Uncheck the boxes labeled "FrontPage support" and "FrontPage over SSL support"
* Click "OK"
* Click "Setup" again
* Check the boxes labeled "FrontPage support" and/or "FrontPage over SSL support"
* Click "OK"

If the site continues to refuse to cooperate with Microsoft FrontPage or forms continue to fail, please contact support with the URL of the page exhibiting the problem, and any additional information needed to replicate the problem.