This may help people migrating to R12:
We were getting FRM-92101 error messages just after upgrading to R12, and then after the upgrade to 12.1...
The full message was:
FRM-92101: There was failure in the Forms Server during startup. This could happen due to invalid configuration.
Please look into the web-server log file for details.
After 3 TARs and lots of traces (the disconnections were impossible to replicate on a specific form), changes, compilations, and re-compilations, the issue has been fixed by a one-off patch from Oracle!
I think the patch is OS dependant, so I won't publish the patch number here.
Regards,
Jairo