I received the same error this morning when migrating a customer from 4.3 to 2014. @PamScott, do you have any third party stuff on your customer's install. We have HT POS and are going to IIG.
On 4.3, I copied their active company to a temporary company code, cleaned up inventory there, removed HT POS data for the temporary company, migrated and received the error. I have looked at the Sy_Module, SY_Activation and SY0CTL and they appear clean. Nothing on new KB. Archive KB article 110-511841 addresses the same or similar issue when migrating from 4.0 to 4.3. See Attached.
I have looked at the SY1Q0x files in DFDM and there is no reference to MR.
One idea is to copy the active 4.3 install to another location, run it, remove POS data for all companies, remove the HT programs and see if migrate to 2014 will work from there. Any ideas?