Yes, as I wrote.
But it doesn’t matter.
Any value should at least bring a graphical session, because IceWM is used as fallback.
And that value is only relevant when you run startx, though it is used as default by most display managers.
But again, Tumbleweed uses update-alternatives now, DEFAULT_WM is not respected anymore.
For the Display Manager, there is a DISPLAYMANAGER parameter, and it looks like it can have a null default value which is what I was asking about.
This is ignored in Tumbleweed since months.
The only way to set the display manager is update-alternatives.
Whatever the @OP has done, he seems to have broken the login screen, and possibly the reason may be related to Plymouth not loading (or at least the problem may be happening about then).
The real problem is not at all clear IMHO, but changing DEFAULT_WM alone definitely cannot cause it.
I guess I’d ask a few questions before concluding that the machine is not functional at all in its current state…
Sure, but it also brings in noise…
If the machine has progressed to loading Plymouth, then it has to have successfully passed the point where multi-user.target successfully loaded which is a working text-only, non-graphical system.
Not at all.
plymouth is started very early, even before the / partition is mounted.
So, I guess I’d ask whether the User can see a blinking cursor or similar…
Boot may be stuck, but is the system interactive or not?
And, if necessary what happens if the system is booted only to multi-user.target? -This is accomplished by editing the grub entry to point to multi-user.target instead of graphical.target
I already asked/suggested similar things.
Again, please read the thread before replying and suggesting the same again.