I have been getting the error below quite a lot in my SharePoint development environment, usually after updating a solution package.

The only fixes I was able to find by searching referred to mysteriously changed casing on placeholders, which was happening, but didn’t help in this case.

It turns out that this parser error actually has nothing to do with either parsing or the page being viewed. It can be triggered by just about anything - in this case it was an error finding the base class for a web part that was never on the page.

The actual error message can be found in the application event log - nothing useful gets added to the ULS logs.

Parser Error

Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.

Parser Error Message: This page has encountered a critical error. Contact your system administrator if this problem persists.

Source Error:

 Line 1: <%@ Page Inherits="Microsoft.SharePoint.Publishing.TemplateRedirectionPage,Microsoft.SharePoint.Publishing,Version=,Culture=neutral,PublicKeyToken=71e9bce111e9429c" %> <%@ Reference VirtualPath="~TemplatePageUrl" %> <%@ Reference VirtualPath="~masterurl/custom.master" %><html xmlns:mso="urn:schemas-microsoft-com:office:office" xmlns:msdt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882"><head>
 Line 2:  <!--[if gte mso 9]>-->
 Line 3: <mso:CustomDocumentProperties>

** Source File: ** /Pages/Home.aspx** Line: ** 1