I open your drawing i v 2017, and there is only one wall there, the rest is surface's, did'nt look at the layers
Somehow you maybe explode the wall's as then they will turn in to surface's, it's not a wall anymore and by that it not cut out for window/ door.
Most easy way is to draw a baseline where the walls should be, then delete the wall's, putt all the doors and windows in a different layer and use them as a snap point when inserting new in the new walls in correct layers, then mark the temporary layer, rigthclik and Select by layer, delete, and you are rid of the old that has no connection with walls anymore.
Most of the times when walls wount heal is if they are not on same workplane, and if they are linked to another wall it will not let you edit everything, so then you need to Select 1 wall and see if there is some other walls that turn blue in wireframe they are then linked, so press shift and Select the blu wall(s) as well and there will turn up a small symbol down on inspectorbar that will let you break the link between them, normally it will be number 3 from rigth ( Drop Link), after that they will be easy to edit.
If the wall only show on 1 side it can be the material, default is 1 side, but you can open the material property and set it to Double sided, then it should show on both side.
If you have 2 walls on same line next to each other you can use Join walls and meke them to only 1 wall in example, they have to be on the same workplane
If you draw a closed polyline; rectangle or something you can use the convert to wall or convert to slab tool on them, and TC will do
I use that function all the time make the shape with a closed polyline, copy it up in different elevations and use convert to wall on them,
and if you use baseline as alignment you can also use them for convert to a slab, especial if the shape is very odd i find it easy to use that function, be aware if you want to do that you will need to make the slab first, as the wall will take away the polyline, the convert to slab dont
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