You may find too that increasing the line thickness of the grid may help, regardless of what colour you choose for it. The automatic grid creates zero-width lines, which can simply vanish at some image output resolutions.

You also don't have to create a single grid across the entire map. As long as you use the same snap grid point to start your grid's placement, you can have several smaller grids wherever you choose, and they'll all line up OK. That way, you can have different coloured grids on the same sheet (though of course, that may not work for all, dependent on what effects you have on that sheet). Or you can set them up on different sheets to get different effects per grid colour.

Might be worth mentioning too that we found a minor glitch with the Sticky Note Dungeon Regular font, which has also been updated in the Annual download now. However, being a font, you usually can't just overwrite this on a Windows system, so you may need to remove the original font first (it should be in the Windows - Windows - Fonts subfolder) before you reinstall.

If you have already done a fresh reinstall though, just remove the font then do a repair reinstall using the Sticky Note Dungeon EXE file, and that should sort it (I have done just this as a check!).

It's always as well to remember to check the information lines on the CC3+ page when you have a symbol ready to place, to be sure which sheet and layer it'll be placed on. You can always change those before or after you place it, though if afterwards, remember to do so! I usually forget to check the layer, as this doesn't always change automatically with symbols...

Also, when selecting anything, always keep an eye on the Command Line (lower left screen corner of the CC3+ window), just to make sure you haven't selected two things when you only wanted one. That's saved me any number of times, certainly.

So far as I can tell, there's nothing actually on the MAP BORDER sheet currently (apart from the usual automatically-generated pin items that retain a sheet in the map file).

The brown frame for the map is on the cave floor1 sheet, however, as is the brown piece of flooring on the right side of the map, and I think this may be the problem. There is nothing else on that sheet, however.

Hide all the sheets except cave floor1. That way you can move the brown frame to the MAP BORDER sheet, which will leave the patch of brown floor on cave floor1.

Not sure if you've seen this FAQ post by Monsen Scott, but it may help.