Dupe Won't Train as Exosuit Engineer

They require crosstraining with general engineer as well as courier. You can see the training requirement path drawn from both general engineer and courier skills. Essentially the same skill training path as mechatronics engineer.

It's possible that there is a tooltips bug with displaying the correct prerequisite job training. If you've trained him for courier, but not general engineer, the exosuit engineer job should say which prerequisite is missing.

Can you upload your save file and logs? They might be useful.

Edited April 13, 2018 by crypticorb

No the crosstraining is for the mechatronics engineer (see picture). What was talking about is the end of the supply training. Seems to be fixed now I exited the game later in the day and he was able to train this time.