You need to draw the selection box first so it selects everything, and then you can do the Combine -> Not -> Fill style -> Solid part.

Thinking about it though, it may be easier to: Change Properties -> Right click to bring up selection menu -> Fill Style -> right click to bring up fill dialog-> Pick the CA101 parchment form bitmap files. There is nothing else in the map that is supposed to use that fill style, so just selecting everything with the wrong parchment works just as well as selecting the forest and then removing the solid lines from the selection.

I am trying to figure out why this is happening, but as a workaround, you can change properties on the fill after placing it.

To do that, first unlock groups (button lower right corner), then use the change properties tool, select the entire forest, but do a selection by NOT fill style solid so you only end up selecting the filled ares, and not the lines, and then proceed to change it to the CA128 Parchment A Medium fill.

However, Hatch Styles are the opposite of good for performance, they will slow your map down quite a lot if you use much of them. Bitmap fills are the best option here.

In this case, this is because you have created a map in the very limited CC3 Dungeon style. This is just a small preview of what dungeon styles can do, and can be used to create simple dungeons, but it doesn't include a cave tool, which is why the button can't find one.

I recommend trying another style, such as DD3 dungeon or one of the other dungeon styles available.

I also notice from the file name in the title bar that you have managed to save your file in the CC3+ installation directory under program files. Don't do that, it is a bad place to keep your maps. I recommend creating a folder inside your personal documents directory or similar.

No, hitting load will load ALL the slots at once from what's in the file you pick. The saved files are a collection of filters, loading loads the entire collection from each file, not just a single item to put into a single slot.

To make a custom setup, you'll just need to type the filters you want into each slot and then save it. This will save a file with the complete set of all slots you have defined, and when you load it, it will load all the slots from that file.

If it were to load just a single slot at a time, it would be impossible to make a file containing many filters at once (which is precisely what you're attempting to make), because you couldn't load it again.

When you load a master filter file, it loads all those slots, not just the first one, you don't load files into slots. Almost all of the existing master filters are using the first slot for the style, because the first one is the one activated by default.

But you can make your own file by filling out the different slots, and then save it as a new master filter file. When you load that file, it will contain he slots as you saved them, and the symbol style toggle button will toggle between those in the list.