We removed the vinyl wallpaper weeks ago. We're currently trying to redecorate, and this is how we are finding all these issues. The mold was all behind a built-in wardrobe we ripped out (with permission).
I say trying to because every time we find an issue, we have to stop and wait months for the HA to come and fix it. Currently, DD's room has no wallpaper/paint because we are waiting for the mold to be fixed, the work in the hall has been halted because we noticed the wall (internal stud wall) is being held up only by the wallpaper, and we don't want to risk it falling down and having to wait months for it to be repaired while we're still waiting on dozens of other repairs.
The kitchen is half-painted, but we had to stop because of a leak, which caused the ceiling to bow. The ceiling cannot be fixed until the wet room leak is fixed, but that needs approval from a manager, and he is not very eager to approve it.
The living room is also half decorated because we had to stop when we noticed damp on that wall.
My room has no curtains because that wall is also damp, and no matter how strong the wall plugs I use are, the curtain pole just falls off because the wall is literally crumbling away.
I'm 100% sure we will find more issues as we go on. Half of these I would pay for/do myself, but I'm not allowed. The bathroom, for example, I hate the wetroom, I've always hated the wetroom. I would happily rip the lot out and pay for a new bathroom to be fitted, but I can't.