My Template Folder has stopped working--it will not open.  In Settings, everything else works. The folders open and the files are accessible. Everything but Templates.  All of the templates do exist in the masterpages folder, I just can't get to them anymore from the UI.

If I try to create a new template, I do get the dialog that asks for the new name. I enter a name and click create.

Then, I get what is one of our custom error pages. It is http://web.windsim.com/errors/page-not-found.html?aspxerrorpath=/umbraco/create.aspx sitting inside of the Create dialog box.

Any ideas are much appreciated!  Thanks!