ID:2239323
 
I apologize if this has been answered, but a few searches yielded nothing.
Is it normal that the map editor's preview box doesn't show anything but blue? I'm working in a 1000x1000 map, so maybe the issue is there.
You have to force update the map (refresh the object tree) more often than not.
I gave your suggestion a shot (clicked 'Update') and this is the result: http://prntscr.com/f1pn1s

Didn't seem to affect it :/
Remove the blue icon from area.
Weird, that usually does it for me (my maps aren't as large as yours though).

You may have found an even worse bug.
Can you really not see the damn issue here? Your area has a blue icon added to it for whatever reason. Even if the blue icon is transparent itself the map editor preview will make it a solid color.
Lmfao. I guess I should post this in bug reports then. To clarify, before I started mapping, even when I just laid out a massive ocean.. There was still no preview, so I doubt it has anything to do with too many different icons.
In response to Kitsueki
Have you tried the same thing on a smaller map?
Yeah, preview works fine lol.
In response to Kitsueki
Just tested using a 1000x1000 map and I couldn't reproduce the issue.

Are you using the latest BYOND build (beta)?
I did just update, let me try again (I was only like one version behind.)

Yep, no preview.
What the hell is wrong with you 2? I just explained what the damn issue is above -_-.
I'm at a loss then. I would advise you post a bug report, but I'm not sure how far that'll go if there's no way to reproduce the issue.
I'll give it a shot, thanks for taking a crack at it.