tranny flushed at a shop and since then the shift inhibitor light comes on on 2004 GMC Sierra 2500 HD

and the truck goes into neutral and i have to shut the truck off in order for the truck to go into gear, sometimes in goes into first gear and i have to shut it off again and the engine light goes off

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2 answers 1 comment
How many miles on it and ahd the trans EVER been serviced before? Probably sludge contamination -How many miles did the shop test drive it , before returning it to you (if any)?
What did the shop say is wrong with it now??
wrong brand green jelly.