Cannot Sign In On 1803 April Update

I just updated my build from 1709 (Fall Creator’s) to 1803 (Spring/Redstone 4), and after a lengthy upgrade process, I go to sign in, but can’t...

The sign in screen appears normally, and I can enter my PIN or Microsoft Password to sign in. However, signing in with either bares no fruit. Each time I enter one and it accepts it, the sign in screen goes away, I briefly see my accent color, and then the screen fades back to the sign in screen.

I attempted to reset my PIN with the provided link on screen. I entered the security code provided to me and after thinking for a second, the screen went black with a cursor, no disk activity. So I force shutdown the machine. After I restarted, it still didn’t let me sign in.

Any possible ideas would be appreciated, I’m gonna try Safe Mode.

So it was either a coincidence or it was the problem, but disabling Classic Shell allowed me to sign in. However, after re-enabling it at startup as a test, I was still able to sign in...?

I guess...solved? Lol what?

MrMii Win 10 said:

So it was either a coincidence or it was the problem, but disabling Classic Shell allowed me to sign in. However, after re-enabling it at startup as a test, I was still able to sign in...?

I guess...solved? Lol what?

It's most likely a coincidence because Classic Shell's menu and Explorer parts does not load until AFTER sign in. Before sign-in, there are no components of it that are loaded in memory. When you sign out, it is unloaded again. It loads simultaneously along with the Explorer shell AFTER sign-in.

MrMii Win 10 said:

So it was either a coincidence or it was the problem, but disabling Classic Shell allowed me to sign in. However, after re-enabling it at startup as a test, I was still able to sign in...?

xpclient said:

It's most likely a coincidence because Classic Shell's menu and Explorer parts does not load until AFTER sign in....

It may not be a coincidence. At first sign in after an upgrade there is a period of a black screen where the user profile is being updated. It may be this process that Classic Shell interfered with. Once the profile had updated, it would be safe to turn Classic shell back on.

It may also depend on whether this 'use my sign-in info...' option was turned on or off...

Regardless, it's functioning as expected. Hopefully it still does after the next major build, since official support was dropped and the program was put back into open source.