FRM-40735: POST-UPDATE trigger raised unhandled exception ORA-04062.

We encountered a strange nagging issue when users were accessing a form through one of the forms server node. They were facing the following error:
ORA-04062: signature of package "APPS.XYCCA_HDRB_EXTN_PCK" has been changed

FRM-40735: POST-UPDATE trigger raised unhandled exception ORA-04062.

We did not suspect the database package because users connected to other three nodes were perfectly fine and were able to open the same form without issues. Bounce of forms server on the erring node did not help either. Environment, db connectivity and all other form server related settings were perfectly fine.

It turns out that the erring node was seeing an "older" image of the pll file referenced by the form. We have a shared file system implemented in this system and the other three nodes were showing the correct latest version of the file. We suspect a NFS cache issue at this time but the fix was to touch a dummy file from the erring node on the file system where the plls were residing.
Unmount and mount on erring node, i am sure, will fix the issue but will require a bounce. In our case, once we touched a dummy file, the erring node started to see the current version of the plls in question and we were able to get past the issue.
- Aravind Kamath Posral