If you have properly installed the controls with the installer and you are using Visual Studio, it should create (or append to) a file called licenses.licx when the controls are dragged onto the design surface. You can see if this file exists by clicking on the 'Show All Files' icon in the server explorer.
If you do not use the design surface, or use the Keyoti.Thesaurus.Model classes directly, then the licenses.licx file must be created (or appended to) manually.
[if the licenses.licx file already exists, then skip to step 3]
1. Right click on the project and select Add New Item.
2. Choose a text file, and name it "licenses.licx"
3. In the licenses.licx file, add the line
(which follows the pattern "<class name>, <assembly name>")
4. Then choose "Rebuild Solution" in the build menu (note, just hitting F5 is not likely to work, until the solution has been rebuilt).
Copying the licenses.licx file to the project directory may still cause licensing exceptions to be thrown when the application calls the thesaurus. In this event, you must add the licenses.licx file to the project, in the Visual Studio solution explorer.