I would be surprised if this had worked. Usually you can't flash a different product type ROM into a phone.I can't use mobile data, and it reboots the phone. RM-938 is not compatible with this specific rom.
First of all, thank you all for your kind and really helpful anders.
So I just flash the old 8.0 rom, using this way: [Tutorial] Unbrand (flash) all Nokia Windows?€? | Windows Phone 8 | XDA Forum and use a product code from UK, INDIA or Finland, correct?
Is it OK to use any Product Code from those countries, or do I have to use a special one from that country? Because according to: Availability in Europe - Nokia all lumia 1520 firmwares are "under testing" lol. So, I'm not sure, if I'm getting the update to 8.1 OTA.
And, of course, you have to use the same RM-code. You can find the RM-Code on your package. Because they have differenct radios etc. An american phone wouldn't work in europe, because of different Radios. So use a product code from the same RM-Code.
Good advice. I did the same swapping from a HK CV rom to a UK CV rom with same color code to get cyan.I don't think you can use any RM937 rom to any carrier specific Phones, this is because they have different hardware like radios. You would just break your phone.. To those who have RM937 and wanted to flash UK unbranded rom make sure you download RM937 match with correct product code and I think its also important to pick the rom for the same color of the phone that you have. I am from Philippines I have Black 1520, installed UK rom a few days ago and enjoying cyan.