Did you bounce the application services and see if this helps?
Please also review (New Required Patches for Patch Wizard, Patch Manager, and Oracle Application Change Management Pack for Oracle E-Business Suite Releases 11i, 12.0, and 12.1 [ID 1267768.1]) and make sure you have all the patches applied.
Yah that's the ID I referred to. I'll bounce the app tier to see if that helps.
If not I'll double check ID 1267768.1.
Just needed to bounce the app tier as suggested. Working now.