I got the message "Register as 'versioned' failed - ORA-02327 cannot create index on expression with data type ADT" a while ago when I disabled versioning and tried to re-enable it.
As a workaround, I found that I had to delete the feature class mentioned in the error message and re-import it from a file geodatabase.
The problem is that with IMPORT you lose the globalid. But simply deleting and copying and pasting from the FGDB didn't solve the problem.
The message has now reappeared - displayed again but with a different Oracle schema. In the meantime we changed the Oracle version (from 12 to 19).
Deleting the feature classes (all part of a feature dataset) and re-importing them from FGDB didn't help. When I copied the feature class from the dataset to a location outside of the dataset, I could sometimes register the feature class as versioned - but not always.
The solution was to use another computer to enable versioning. I don't know why this solved the problem - we have the same version of ArcGIS installed on both machines. The only difference I noticed is that the computer where versioning activation was successful did not have a language pack installed.
One more thing to mention: I first did exactly the same thing in our test database and didn't encounter any problems when re-enabling versioning.
