Weird Shadow That Keeps Following My Viewport

I’ve had this since forever and only now did I have the patience to seek help for it.

(Can’t upload GIF so here’s a link instead)

I’m talking about this weird diagonal black shade on the ceiling. It also pops up walls once in a while as long as you’re viewing it from a strong enough angle. It even shows up on Cycles render, blacking everything out. Has anyone else encountered this?

Upload an example file and don’t crop screenshots when asking questions

My bad, I was trying to keep it clean. Here’s an uncropped screenshot.

I’m trying to clean up the 255MB .blend file so I can submit it. How do you remove all the unused textures? I’m trying this and I’m trying to make sense of the python commands. I enter them into the python console but nothing seems to happen. The file size is still 250MB

Pardon me for asking so many questions, but how do you close this top window? I can’t drag the neighboring windows into it

Yes, 255 MB is too big. If they’re image textures, the images themselves are external assets and won’t be included in the file without explicitly packing them in. If they’re not packed, something else in the file takes so much space. Maybe you have some images packed in, hdri files are big for example, and the rest is geometry.

The reports you’re showing are part of info editor at the top. Drag the top header back up. It’s actually part of the info editor and rest of it is usually hidden.

You seem to have at least renamed the scene. If you have multiple scenes, check scene properties -> scene: background if there’s another scene set there. If there is, that’s where you might have another object that appears in this one.

Scene properties in #3

It’s possible that while preparing an example .blend for upload you come across the culprit. Could delete most of it, maybe all of it, but it’s important that you’re still able to see the problem with the file you upload. But if you don’t care what causes it, could start a new file and file -> append, browse to your saved file and open it, and import objects or the whole scene from that and see if the problem goes away.

I GOT IT! Thank you so much! I know exactly what causes it now! I forgot to plug in a normal map node in between the normal texture and the socket in the Principled BSDF

But, it seems I made the top window infobox thing angrier, as it’s growing larger and I can’t even drag it upwards to scale it down.

Please help me out with this it’s taking so much space of my little screen

EDIT: Oh it’s gone. I had to click on the very bottom of the info menu. All is well now!