Failed to load AOT module ... in aot-only mode.

I’ve changed very little from this build to the last but now I get:
Failed to load AOT module ‘mscorlib’ while running in aot-only mode.

Found the solution here

**Problem**: Program crashes and debugger reports: “Failed to load AOT module ... in aot-only mode.”

Possible Causes: Unknown cause. Possibly another bug in the Unity iPhone build pipeline.

Possible Solution: Delete the app in the device (using Xcode Organizer) then install it again.

95**EDIT:**95 so I think this was caused by changing the system date to the future, doing a build, then setting it back to the correct date. In the end the solution was to delete the derived data and the app from the device, then rebuild the project from Unity…