#ERROR for Project Custom Field Formula

A co-worker was having a problem with Project Server 2007 where any formula put into a project-level custom field would come back with #ERROR. It did not matter whether the formula was a calculation or just a reference to another field the result was #ERROR in Project Professional. (It would show up blank in the PWA Project Center.)

Task and resource level custom fields with formulas continued to work properly.

There were no errors in the ULS logs, SQL logs, or Event log.

We flipped emails back and forth to attempt to address the problem:

• Checked Project's calculation mode -- it was automatic
• Closed and reopened Project
• Cleared local cache (in case of corruption)
• Created a simple formula (=1) -- it still failed

Eventually we struck gold when we checked other formulas for problems or corruption. There was an old custom field with a formula that referenced another custom field that had been deleted. It was failing and all of the formulas calculating after it were failing too.

Once we removed the problem formula and did a recalc, all the results from formulas showed up correctly.