You shouldnt use cgs subtract. There are times when you could use it but 90% the time the time you shouldnt. Even the 10% you could Id still suggest not using it.

As you noticed it creates weird outcomes.Also can greatly increase build times as well as leave artifacts around the areas in which you used them.

Its been brought up around here quite a few times. Its better to just use edge and vertex move mode to build doors,windows ect... If your unsure what I mean I have a short video on my site that builds an arch with out using cgs subtract.

As far as the blocks being untextured theres probally a face or something that isnt.

I suggest after building a level and about to texture it assign a texture to the entire level and set its flag to none. THen you can go thru and texture what needs to be textured. Any of the blocks set to none will not be rendered which can increase build times and up Fps while the game is running.

Personally I created a hot pink texture which I use for such a thing. Its easily noticed during the texturing stage so you can tell if you missed a block.

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