Every once in a while some confluence of events causes my Developer Express controls to disappear from the Visual Studio toolbox. I am not going to be an apologist for this, but support are having problems reproducing this problem. (If any of you have any hints they’d be appreciated by all.) I think it is annoying and would like to see the problem permanently resolved, but if it happens to you here is what you can do to quickly and painlessly re-register the controls with Visual Studio.
To re-register DevExpress controls with Visual Studio click Start|All Programs|Developer Express v2009 vol1|Components|Tools|ToolboxCreator.exe (clicking on the ToolboxCreator.exe executable). All other variations of running this command results in the dreaded error dialog (see Figure 1). Make sure you close Visual Studio before running the ToolboxCreator.exe utility.
Figure 1: Avoid this command and re-register your Developer Express controls with the ToolboxCreator utility.