IEMode No longer working on Win10 v1607 systems?

We've got a few systems stuck on v1607 for now. Previously IEMode was working fine, however it has stopped working... Not sure exactly when this occurred.

Getting message to re-install with Admin rights (we did, via SCCM with the system-level flag).

As far as I can tell by the system requirements page for IEMode, it should still be working?