I have been struggling with this plug in for about 2 months ... sometimes I can get it to work, but generally, it puts circles where the tabs are to go, but does not slice or print them.
I have finally figured out how they work, so if you are having problems, there are a couple of simple steps to take ..
Enable 'suppports'
make sure 'support density' is set to 100%
make sure 'support angle' is set to 90 degrees. (this stops the slicer putting any other supports in place)
now just select your model, select Tabs+, and place them where you want them on the model.
They should now slice and print ...