The Problem
A customer was experiencing strange ‘access denied’ errors when attempting to their home page (http://portal.somewhere.com/). It appeared very random in nature and we were very confident that permissions were not the issue. Server event logs and ULS yielded no results either.
The Solution
It appears the problem is that the Wiki Page Home Page Feature sort of ‘half activated’. It wasn’t activated in the feature list but remnants of what it creates were. In other words, there was a sitepages library created but no pages in it (home.aspx being the default/important one). As well, when this feature is typically turned on the home page is redirected to /sitepages/home.aspx. In the end, the fix was to go into SharePoint Designer and reset/force ‘Set as Home Page’ on the default.aspx page
Figure 1 : Screwy but this did the trick