Operating system: Win 10
Graphics card: Gtx 1070
Short description of error
It seems like once in armature pose mode, it is impossible to select or click on a regular object. This is no issue in 2.79. One can select objects directly while being in bone pose mode.
Exact steps for others to reproduce the error
Load the attached scene (It should open in pose mode)
Try to select the cylinder mesh that is deformed by the armature
Clicking on the actual object in the scene collection tree listing does not help either.