ReadyNAS Surveillance license re-activation

I did a factory reset on my trusty Pro Pioneer (RNDP600E) and  I thought I had done what I needed to do to keep the license activated - i.e. by keeping a copy of the license number and exporting a license registration file (offline.req) to the PC from within the ReadyNAS Surveillance app.  

Unfortunately, having done the reset, the ReadyNAS Surveillance app is not letting me re-activate it either:

(1) via online registration with the license number - this gives an "error code 11"; or

(2) via offline registration - the "OffLineTool.exe" will not generate an offline license file (offline_license.dll) from the exported "offline.req" file and also gives an error code 11.

Is there anything I can to avoid / resolve error code 11?

Does someone netgear​ need to do a license reset?

Any suggestions to solve this would be greatly appreciated!!!