It means that there is an issue with your Project Details views. Based on what I have seen in the past, it could be related to a bad filter/custom lookup table.
What I would suggest is this:
From Server Settings >> Manage Views>> project section, temporarily disable the default view that appears when you click on a project name (by removing all categories associated).
See if you can default it to a view that standard and does not contain any of the custom fields.
If this works, then the enxt step is to figure out which element is really causing the issue.
If you have access to the Server where the ULS logs are stored, that will give you some clues as well.
