Error with Doom Builder

I have been using Doom Builder for a while now. A problem I've been having was when Doom Builder worked, and when I went to test a map, it came up with "Error -2147221504 while saving map; spaces not allowed in key names." And I haven't put any spaces in anything >.<. What's wrong with it?

Have you modified any of the configuration files ? Try testing\opening your wad with another configuration, if you can.

If all else just reinstall DB.

Maybe a space in the map name? Spaces in your map name 'corrupts' the .dbs file when the map is saved. Simply removing the .dbs file before you open your map solves the problem in this case.