@ciprigfh
I think you may have confused the instructions. EITHER you directly use the supplied QuickCure3.rgn (unchanged, just safely renamed appropriately as XXXX01000xxx.rgn - see below) OR you use the device's actual firmware to make the Cure3 RGN. It seems like you're trying to make the Cure3 fw from QuickCure3.rgn. QC3 is ready to use after renaming, "XXXX" being your device's HWID and "xxx" being the current fw version loaded to the device, e.g. 290001000154.rgn. Whether you use QC3 or Q3 the RGN's safe-naming convention is the same. Best try with QuickCure3 first as it usually works, but Cure3 always works to re-enable Mass Storage Mode in compatible devices.