SharePoint Designer 2010 Can't open Page Layout in Edit Mode

Every time I try to open any page layout in my site collection SharePoint Designer 2010 throws the the following error at me.

Can't figure out what's wrong. I've us开发者_运维百科ed it fine with other site collections before.

Any ideas?

when opening your site collection, try to specify the full name for this collection. for example, instead of http://localhost, try something like this: http://fullname.domain.com

Or, probably a better way to fix it: go to Central Administration (/_admin/AlternateUrlCollections.aspx) and check your alternative access names. When you open your collection in Designer you have to use exactly the same URLs.

I have since found out what caused this issue.

I was missing the following handler for asmx within my web.config file

      <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />