Hi Dax,
The RadControls SkinObject / Modules are not yet updated for DNN 5.1.2 and it is possible that there are changes in DNN 5.1.2 that break the compatibility if RadMenuActions.
If there are no major problems, we are expecting the SkinObject / Modules package to be updated and fully tested by the end of next week.
Thank you for your understanding.
Best wishes,
Dimitar Milushev
the Telerik team