Its the typical Windows message that says, DesktopX Builder has found an error and has been closed, we are sorry for the inconvinience. something like that..

Try restarting your computer. Its done the same to me but with a differnt theme,widget. I just restarted computer and it worked fine. If that dosnt work maybe reinstall DesktopX.

notepad can work
there'a also object edit that comes with the full package

I think you need to uninstall DX and re-install again. Sounds like something got corrupted during the install. This program does usually work like a charm.

First, always clear your DXCache if you are having a repeating problem like this. That can solve a lot of problems. Clearing the Cache 101 by Corky_O

It could be some conflict in the theme as it is being shutdown and reloaded for the switch from dx to dxbuilder. Try loading DXBuilder as clean / empty desktop. Then import the original theme file directly into the builder.

I doubt it has anything to do with your installation. In the past I have experienced similar behavior, but it was sporadic. When I have been able to find the problem it was usually in the scripts of the widget itself, not a problem with DesktopX. Although I suppose it could deal with the problem a bit better.