SP-RDM2 Reader Expanders running firmware 1.12.544 appear to fail whenever an attempt is made to update their firmware revision.
There is a known defect in 1.12.544 (Build .544) which prevents the SP-RDM from being upgraded or even downgraded. However, a number of SP-RDM units have been shipped from the factory with this build pre-installed.
Any attempt to select an SP-RDM running this firmware and upgrade or downgrade it to a different revision will consistently fail with an Error: 'Module not responding'. There is also a possibility that the SP-RDM can be permanently disabled in the process
Since the .544 Build Defect cannot be resolved the only recourse at this time is to swap out the unit via the Returns Material Advice (RMA) process for a new unit.
Note: All other SP-RDMs running firmware both above and below .544 Build are unaffected