If you have access to Acrobat Professional, it may also be worth trying to feed it through the PDF optimizer, flatten the structure of the file.

Those old PDF's are pretty cool, because they contain actual vector data from CC3+, making them have the same "infinite" zoom capability that the original CC2 map it was made from. But unfortunately, that also means it is highly complex, which is why it probably crashes your readers now.

And every citizen in every city prays it won't decide to come out and play with them.....

The black background usually means that CC3+ cannot find the map file it is trying to load, so it simply uses the defaults (which is a black background). That in itself is nothing to worry about, as the background is controlled on a map by map basis. Everything will be fine when you load or start a new map.

Of course, the example map should have been loaded, so that seems to indicate you didn't get that file installed. Which may or may not indicate that the rest of the addon wasn't installed properly either. Best way to see that is to try to open the symbol catalog manually and see if it exists, and no red crosses in it...

Now, I see it is trying to show the no-SS6 version of the example, since I guess you don't have SS6, and I am guessing someone forgot to include that file in the installer (or gave it the wrong name), and the rest is fine..

Now added to the atlas. Thanks for contributing.

And here it is in the atlas. Thanks for the contribution Wyvern.

This is a special case that happens with symbols. The thing that happens is that all symbols have their definition on the SYMBOL DEFINITION layer. And if you hide the definition, the symbol disappears. So symbols will always be hidden either if you hide the layer it is on, OR if you hide the SYMBOL DEFINITION layer. So if you are trying to get to an entity by hiding all the other layers, make sure you leave SYMBOL DEFINITION still visible.

As JimP says though, it shouldn't be on the MERGE layer, so use change properties on it to put it somewhere else.

If you only want smaller symbols, that is quite easy. After starting a new map, just hit :CC2PRESETS: and change the default symbol scale to whatever you want. If you want 5 times smaller, just set it to 0.2.

Note that this just changes the default scale, not the current one, so either save, close and reopen the map as this will open it with the new defaults, or simply click a symbol, and with the symbol on your cursor click in side the map area to bring up the symbol parameters dialog and hit "set normal" and the current setting should be changed to the default.

All tools that place symbols should observe that default setting.

Maybe Shessar's North Alarius map in Sue's spectrum overland can provide some ideas.

Grids are just entities, you can use change properties on them and make them as wide as you like (They're usually on a frozen layer, so thaw it before attempting to manipulate the grid). Other things that also usually work very nicely is to add a small glow effect to the grid.

The default line in CC3+ is a line that is as thin as possible (which usually translates to a single pixel). This works fine on screen, but can lead to nearly invisible lines on prints/exports.

You might also simply not be increasing it enough. Keep in mind that when exporting to an image, you take a very high-detailed setup in CC3+ and tell it to squeeze it in to a limited number of pixels. This means something sometimes have to give and give up some of their pixels to other elements in the map. An line can feel plenty thick in CC3+ itself, but when competing with the rest of the map for those precious pixels, it may still be too thin for export.