I noticed something by coincidence, I was using the new simple Rig Tool
-I created a simple Rig
-created a new Controller, then I pressed ((Edit Pivot))
& I changed the scale of the controller directly with Maya Scale tool
-pressed ((set Pivot))
-then I needed to add a geometry to this controller
-I made sure that my controllers are in Reset position of course.
-so, I tried to add that new element to this controller, BUT mGear refused to do it & gave me this error :
The control: EXTRA_C0_ctl should be in reset position
I made several trials & I found that this issue happens if I scaled the controller in Edit mode, it doesn’t happen if I change the x,y,z position, just happens with Scaling!
If you may ask why I scaled the controller? after mGear created it, I felt its size was a bit bigger than needed, so I wanted to scale it down a bit.