Samsung A3 SM-A310 FRP issue
 

I have an SM-A310F
USB debugging was venabled / OEM Unlock was enabled.

Rooted via Odin and CF

Worked well.

Then OEM Unlock turned off in Developer section.
Handset fails to boot with a message
"Custom Binary blocked by FRP Lock"

is there anyway to get past this and boot handset without factory reset / firmware upgrade and data loss

Any help appreciated.