This page lists various encountered errors, that may occur during the BSP map-compiling phase.

All QuArK supported games, are know to use a BSP map-compiling phase:

Error: parsing entity 3, brush 0, side 2 : expecting '(' got '32'

Getting an error similar to the above, usually means that the .MAP file isn't in the correct format, for the build-tool to understand.

Please check:

• Are you using the correct build-tool for the correct game?
  For instance, it is of no use, to have a Quake-1 build-tool compile a Quake-3:Arena .MAP file, as the internal structure in the Quake-3:Arena .MAP file can't be understood by the Quake-1 build-tool.
• Have you set up QuArK to the proper game-mode?
  Make sure that you have selected the correct game-mode, for the game you want to make maps for.
• Did you try to convert a game-A .MAP file to a game-B .MAP file, using QuArK?
  QuArK can't always do a useful conversion of .MAP files, from some game to a different game. When doing this, you should experiment alot to see what can and what can not work.

I don't know why this message sometimes pops up, resulting in large gray areas in Quake. My modest experience on it seemed to reveal that this error sometimes occurs when you stick a polyhedron into another one, if one face on a polyhedron ends up completely inside the other polyhedron, and if this face is not axis-aligned, i.e. it has a slope or orientation of something else than 0, 90, 180 or 270 degree. I got the above error after I slightly moved a polyhedron into another one to avoid a small gap between them, and all three conditions were suddenly met. The problem disappeared when I put the polyhedron back outside the other one.

This is not a map error : it is just a bug of QBSP ! For some strange reason, although a .map file only contains definitions of planes, QBSP ends up with vertexes out of their plane... This is not an error in your maps. Just use a version of QBSP that only issues warnings instead of crashing when it runs into the point off plane problem. There is nothing more to do about it - out of maybe rewriting parts of QBSP itself. But it works anyway. Someone said that "point off plane" occurs when you have a polyhedron with a side which vertexes are not all in the same plane. This is absolutely wrong. .map files on which QBSP works can only contain plane definitions and no vertex coordinates. Map editors that let the user create such strange polyhedron are just a hack in the sense that if you save your work in a .map file and open it again, the strange polyhedrons are flattened out. Of course, because the map editor had to arbitrarily choose a plane to write in the .map file. I don't know how it can choose a plane when there is none containing all the vertexes ! They probably just compute the plane containing the first three points and drop the other ones.

ERROR: MAX_TW_VERTS (12) exceeded

Every game engine has its limits. You just exceeded one of them. Depending on the error, there may be ways to fix this error, or there may not.
There sometimes are other game-executables available that increase these limits. You'll probably need an adepted compiler too, but remember: anybody trying to play your map will need the changed game-file too!

Here's a list of limits in Quake 2: