SharePoint is a fickle beast, and moving from SharePoint 2007 to SharePoint 2010 has the potential to produce the expected problems. I recently moved a SharePoint 2007 site collection to SharePoint 2010 by importing the 2007 database on the 2010 farm.
I was stumped for a bit on an error that was unspecific and didn't really tell me what the problem was: "One or more field types are not installed properly. Go to List settings page to delete these fields."
This error was impacting the Pages library and popped up when any page in that library was loaded. No reference to a specific field type appeared in the actual error (even with custom errors disabled) and there was no reference to the specific field in the ULS logs.
I went as far as to look at the exception site in code using .NET Reflector. Finally, I ran across the article below that directly identified the issue. The problem originated from one of the hidden lists in SharePoint that is used for the Publishing Infrastructure called "Relationships List".
Location: http://<site_url>/Relationships%20List/AllItems.aspx
It wasn't even referring to the Pages library! I guess they forgot to mention in that error that they were talking about a different list. Apparently, the upgrade process doesn't fix everything. Not that surprised.
Reference Article:
Chanakya Jayabalan: One or more field types are not installed properly...