So which camera do you have: an OM-5 made by OM System or an EM-5 made by Olympus? The latter is fully supported by RT while the former not yet.
At least, that is my understanding. (But perhaps one of he development versions of RT does support the OM-5) The orf files from my EM5 MKIII and EN10 MKII work just fine in RT5.9.