If there's a line of effect between you and the target, no matter how circuitous it is, the target is hit. If there isn't one, it has total concealment and can't be targeted. If you're going to ignore RAW and play like a reasonable person, just let people target the wall.

It just says you can cast it on a creation of magical force, such as the wall created by Wall of Force. It does not say that you can do it without first casting See Invisibility. Though would that work? The wording in Disintegrate lists a creature or object separately, implying a Wall of Force is neither. Since See Invisibility only lets you see creatures and objects, it wouldn't let you see a Wall of Force.

There are two fun things you can do with D&D. You can be pointlessly pedantic with the rules, and you can play. As long as you don't do both at once you're good.

Usually not when actually playing, though sometimes it can be. For example, by RAU, if you cast Imprisonment (Slumber) on an elf, they'll be immune to the part that makes them sleep, but still get immunity to aging and hunger. It's not OP for a ninth-level spell, and it has interesting worldbuilding implications, so you can just run with it.

If they don't have total cover, they're hit. Nothing says that disintegrate needs line of sight. If they do have total cover, they can't be targeted.

I thought it was funny, to be fair

Oh, true. It had slipped my mind that see invisibility allowed you to see things that were innately invisible and not just things magically made invisible. Well now I just look foolish!

Tired of pesky adventurers always seeing your tricks? Try applying Invisible metamagic to conjured Fog today!

Personally I used to love it, if the DM did that it inspired players to play; usually whoever had theage would say something like I can't destroy what I can't see and the the fun starts... Someone throws flour from their pack at it (or dirt, oil, something to make the invisible object visable in another way). I haven't played in over 20 years so I'm sure it's changed a lot but that kind of stuff was fun to me.

I mean that outlook, while it's cool for your campaign, it would make raising the dead (to fight for you) pretty difficult as I thought most animate dead type spells required a dead creature to animate and wouldnt work with an object, otherwise people would just make small effigies to animate instead of summoning the dead in battle.

I understand where you are coming from, but it think there are plenty of opportunities for improvisation and creative solutions without the need to start splitting hairs about specific wording.

I feel that people not following the wording kills a lot if the experience, obviously the DM is god and makes final calls but, some stuff kills it. I remember playing with one guy that wanted every fight to be epic but he didn't really understand the wording in the monster manual so he would constantly throw huge battles at us and underpower them or just play them weird (like dragons that aren't smart despite their int score). Before ever seeing level 15 our characters could have taken out God's with the gear and crap he had given us. Fun memories though so I guess it really doesn't matter, it's all about how you like to play.

No I don’t want to play RAW. I just don’t want in game solutions to out of game problems. Just (and I know that this will seem extremely absurd, but hear me out!) talk to your players about it like a normal person and make it clear before you start to play.

I actually think it’s funny too.

I was extremely baked when I asked that but I think it was a question about how some light will reflect off your eye into your eye therefore you're seeing your own eyes.

As hilarious as that is, are you sure that being immune to the form of imprisonment doesn’t just make the spell fail?

Responding to your edit: You've got it the wrong way around. What you see at sunset, the reds and yellows, _that's_ the sunlight being filtered because those wavelengths make it through stronger. Your argument would hold there, if we do not count seeing filtered light as "seeing" the filtering material. But the blue sky is not that. It is the air molecules being illuminated by light coming from somewhere else, and bouncing that light back into your eyes, with a bias towards blue wavelengths. If that does not count as "seeing" air, then you also can't actually "see" fog, it's the same mechanism.

I guess having floaters, or that weird effect of seeing your white blood cells in the capillaries on your retina would probably count haha

Are you saying the example in this meme is good way to follow the word of the rules?

Finding loopholes is one thing, focusing on finding them so that you can "erm actually" a god is another