It still crashes, and now it's acting really strange...
First, using a Pledge Teleport Scroll after operating the door no longer causes a crash, but the door completely disappears visually. Since the invisible door is still physically there, I can't walk outside, and clicking on the invisible door does nothing.
If I talk to the Housekeeper while in this state and operate the door through them, the invisible door reappears. But if I then use a Pledge Teleport Scroll after that, it crashes.
After that, things get even more unpredictable:
・Just walking inside the house while the door is invisible can trigger a crash.
・Logging back in after a crash and simply using a Pledge Teleport Scroll can also trigger a crash.
However, taking a random teleport once seems to fix everything until the next time I operate the door again.
What all these fixes seem to have in common is:
・Once the door is operated, a crash is bound to happen somewhere along the line.
・Taking a random teleport completely clears whatever is causing the issue.
I wonder what's hidden in that door... If this is too tough to fix, I guess I'll just avoid touching the door altogether for now.