I had some trouble rooting after I first did a 4.4.2 OTA. So I downgraded to 4.3 and got root and installed TWRP without any trouble.
So from a 4.3 firmware I went to Cyanogenmod (Android 4.4.2). Is that ok ? Or do I need to upgrade radio, boot or other parts that dont come with a custom rom? In other words: is a (rooted) 4.4.2 firmware a precondition for installing alternative 4.4.2 roms?