Windows PE: Powershell is not installed & error 0x80070002

Trying to run a task sequence. In the last step, I'm trying to run a powershell-script to install various IIS-features. At this step the task sequence terminates with an error (can't remember error code atm). In the smstslog it said that "Powershell is not installed".
I then mounted the image in question and added all necessary packages to it (followed this article).

When I boot into Windows PE and chose the os image, I see how it's actually downloading the boot image (which should now have Powershell included). After the download it tries to apply that image, but then fails with the error 0x80070002. Some research reveals the error might have something to do with bad network permissions and / or that it couldn't find the image on the network share. Both, especially the latter option seem illogical to me, since it was able to download the image in the first place.

Any ideas as to what else could be causing this error ?

Error may be due to the MDT verifies PSversion. If you have MDT loaded with ADK 8.0 you will need to add a line in the ZTIPSUtilities.wsf file that checks for PS version >= 3.0. Otherwise it only looks for 3.0>.

Otherwise you could just upgrade to ADK 8.1 or 10. I recently experienced this issue and was throwing erroneous errors. Modified the wsf and error is gone.

Good luck.