On PhpStorm version 2017.1.3 but I think that this error is present on any JetBrains IDE with database support.
When I choose to synchronize an Oracle schema, some objects like triggers are not shown on database and I found an error on the log.
I could not find any reason and it was working on older PhpStorm / DataGrip version (before 2016.1)
In the options tab I've added an object filter. Without it there are 5000+ tables. Even removing the regular expression on the object filter I still have the same error.
Capture of Options and Advance Options. The oracle client used is Thin.