Bryan emailed me back a short time saying he had "found the solution and it's pretty cool. You should probably blog about it, but you have to give me credit. :)". Better yet, I convinced Bryan to be a guest blogger here. So, without further adieu, here is Bryan's writeup:
The issue was encountered with a 22.214.171.124 system being upgraded to 126.96.36.199.
When we attempted to upgrade 188.8.131.52 to 184.108.40.206 using the Oracle installer, the “Apply maintenance release” option was disabled. Click on the graphic below to see a full size copy of the dialog.
We determined the original installation was performed while logged into the Windows server as
After some research, we found the initial installation places a small file, called oracle.products, in the users home directory (i.e. C:\Documents and Settings\
The lesson for all of us doing infrastructure work is to always perform installation steps using a permanent, non-expiring ID. When I set up an environment, I typically ask for a non-expiring ID that will be used for the installation and to run the EPM services. If you run the install using this ID, you would never run into this issue during subsequent upgrades/patches.
Thanks Bryan for sharing this information!