If you are really interested in object tagging or other such new features from 126.96.36.199 or any other features from version 188.8.131.52, you will see some strange behaviour.
We saw something similar when trying to enable ‘object tagging’ in Siebel 184.108.40.206. The error simply said “ERROR:: Development Tag is not associated to this user” while starting Siebel Tools. It did not throw a lot of clues in Support site or anywhere else, but the logs did say that a required Business Object could not be found. A quick check revealed that the SRF being used by the Sample Tools dated back to 2012, which implied that it did not have the latest definitions. Apart from working with Oracle Support, we just full compiled the sample database and replaced the Tools SRF. This resolved the error.
I did read somewhere that one of the steps in the maintenance release (most likely QFs), was to recompile Tools SRF. A blasphemy during good, old times, but all of us have changed (hopefully for the better).