I have a problem with not being able to see the encounter bar on my UI, it's the one that pops up to do stuff like track the Hozen in Brewery 5man. I am convinced that Dominos is the culprit as if I disable that it works fine.
None of the settings in Dominos are set to disable that bar or hide it etc...
Type /dom config and find the Encounter bar - then make sure it is enabled (middle click to enable/disable). If you don't have the encounter bar, make sure the Dominos Encounter addon is enabled.
It might also be another addon that is interfering.