The tool to upgrade previously existing custom numeric limit step types to add EQT support is now available on this KnowledgeBase article:
Custom Numeric Limit Test Step Type Shows an Error in Step Settings in TestStand 2016
Additionally if you are not using the EQT feature, this scenario should no longer produce an error as of the f2 patch for TestStand 2016.
Regards,
Kevin Flanagan
Product Support Engineer | Automated Test Software
National Instruments