I cant seem to install magisk nor /e/ os custom VBMETA (that was provided with the OS build) It isnt even in kg: prenormal when I installed custom vbmeta. And i keep getting this error no matter what i do.
“Security Error”
“This phone has been flashed with unauthorized software and is locked. Call your mobile operator for additional support. Please note that repair/return for this issue may have additional cost.”
(red text and black) Only official binaries are allowed to be flashed (vbmeta)
I guess you are aware that this is very much associated with RMM or KG Prenormal. The Odin Mode screen on a “newer device” may not display the status of KG or RMM State Prenormal. [1]
In my brief reading it looks as if Odin flash of Stock ROM might be called for.
You are booting into Download mode OK – neither the device nor install page really describe the way that connection of the USB Power seems to work as a trigger.
@kevin7711, it is impossible to install /e/OS-T with this firmware 500XXS7CXB1! See my experience here
On the other hand, installing with LineageOS 21.0, LineageOS21.0-for-microG and iodéOS 5.1 works perfectly. These three CustomROMs are based on AOSP 14 (Android 14 'U’pside Down Cake)