I have attached a small example that triggers an ICE. It happens when I assign values to the real and imaginary components of variable with intent out in subroutine. This is with 2017 XE on Windows 7. Please let me know if you need any other information.
Thanks - being able to assign to %IM and %RE is a new feature in 17.0 and it looks as if there are still some issues to be worked out. I'll send this on to the developers. Issue ID DPD200414426. I didn't find that the INTENT mattered.