Minecraft – command to spawn blocks in the air with worldedit

I suspect you used /gamemode 2 [player] instead of /gamemode 0 [player]. Gamemode 0 will take you back to survival, whereas gamemode 2 places you in Adventure mode, where no blocks can be destroyed, except with the right tools.

Instead of a number for the gamemode, you can use the full name (survival, creative, adventure, spectator) or an abbreviation of the name (s, c, a, sp) to avoid this mistake in the future.

There is a list of Mappers on the Minecraft Wiki.

There are not too many that work with 1.8, but I will list a few that seem to work for your problem:

• MCAMap is a tool that I have used before. All you need to do is point it to the world folder and render all the region files. Make sure not to make the quality too good, or it will take some time to render. Officially, it supports only 14w11b, though I don't see why the 1.8 release version wouldn't work.

• uNmINeD seems like a very nice mapping software, 1.8 is officially supported. I haven't actually used it though, so I can only vouch for it based on nice screenshots. No idea as to the speed as well.

• Minutor Reasonably quick and straightforward. 1.8 supported. You have to open the world folder rather than a level.dat