When you outline a multipoly, the outline itself also becomes a multipoly. Amultipoly is always a filled entity, so you cannot set line width on it. That thin outline you initially get is the Hollow fill style, which is the only way to have an outline with a multipoly.

However, the main reason for having a multipoly in the first place is so you can have a hole in the poly. For the outline, this is kind of irrelevant because it isn't a solid surface you need a hole in. So you can explode the outline you get, and then use change properties on it (remember to pick all the entities that made up the outline multipoly), and set the fill style to solid, color to black, and a line width of your choice.

When you visit this forum, you'll see at least two notification banners appearing at the top of every page. One telling you about the latest CC3+ update, the other a welcome message with a link to the posting guidelines.

Notice that as long as you are a logged in to the forums, you can dismiss these permanently by clicking the X in the top right corner of each. Don't be afraid to dismiss them, while there isn't a way for you to bring them back, the link to the posting guidelines is always found in the sidebar anyway, and if a new version of CC3+ is released, the banner will be back, you don't need to keep it around to get that reminder. It is actually better to dismiss it, as a new banner popping up is more easy to notice than small text changes in the one already there.

From time to time, there may be other banners there with important information, and some pages have their own banners. These may or may not be closable, depending on the message. If they aren't closable, then they're not designed to hang around for long though, these are typically short-term messages like notifications of upcoming maintenance and the like.

Of course, if you do not log in and just browse as a guest, these won't be closable, as that state is stored in each user's account.

Yea, as I mentioned above, you cannot edit a multipoly properly, which is why this should be the last thing you do.

To edit the multipoly, you need to temporarily disable it.

1. Hide your walls to avoid accidentally messing with them.
2. Use :CC2EXPLODE: on the floor entity. You'll notice that your "hole" disappears, but that piece of floor we used to make the hole in the first place should still be there, although it may be difficult to see.
3. Show the walls again.
4. Do your edits. (Note that we did move your walls to other layers/sheets, so make sure the oultine entity of your drawing tool is updated with the same changes, or it might not work properly)
5. Hide the walls
6. Use :CC2MPOLY2: again to combine the floor with the hole.
7. Show the walls.

Did he look in the cat bed? Cats steal things all the time. Good place to find lost items.

As you yourself conclude, the main issue is that many of these things are defined as percentage of view width, while the actual preview window is a fixed size, so this can happen with extremely large maps like this.

So in short, nothing is broken, just a view issue.

You can actually change the size of the preview windows, if you hit that advanced button in the drawing tool window, you'll have access to the sample width setting, which is the size of the preview, just bump this up a few notches. Do note that this is a per-tool setting.

At this stage, the bitmaps may look more pixelated than desired too, so you may wish to use :CC2RESMODE: to force a higher resolution for the display (Note that this can affect performance)