After the Android P DP1 hit, a couple of other folks reported working into problem unlocking their bootloader if it wasn’t already previous to flashing the developer preview. Seems, there’s a repair, and also you shouldn’t have to wipe your software. Merely disabling no matter lockscreen safety surroundings you will have is sufficient to sort things. 

The issue, on this case, is beautiful easy. The “OEM unlocking” toggle in Developer choices that governs your skill to free up the bootloader in Fastboot may seem to paintings, but it surely in truth simply insects out in case you attempt to use it. After verifying your safety main points, it simply toggles itself proper again to off.

On the time, we suspected manufacturing unit reset may well be required to sort things. Google had any other an identical downside that still required a complete wipe as a repair. But it surely seems all you want to do on this case is disable your lockscreen safety (i.e., the pin, password, or trend that protects your telephone). We will be able to ascertain that, as soon as the safety is disabled, the toggle will paintings as anticipated. You’ll then re-enable no matter protections you prior to now had in position.