Hi

I have used XS++ to get this information (updated CID from 51 to 52):

13:25:10| Baseband ID: 9900
13:25:10| Protocol Version: 3.1
13:25:10| Phone name detected!
13:25:10|
13:25:10| Profiling SEMC phone...
13:25:10| Platform: DB2020
13:25:10| OTP CID: 51
13:25:10| EROM CID: 52
13:25:10| EROM Color: Red
13:25:10| IMEI: *
13:25:10| Phone ID: K550
13:25:10| Region: EUROPE_4
13:25:10| CDA: CDA102743/35 R2A
13:25:10| Firmware Version: R1JD001
13:25:10| EROM: R3A016
13:25:10| Ready for operation!

So I am good to go. In the tutorial, it says "2. In Windows Explorer drag (Windows drag and drop operation) the MAIN firmware (*.mbn)". But which firmware should I use? I guess K550_R1JD001_FS_EUROPE_4_RED52 is the correct one, but which MAIN?