Hi Emmanuel,
Thanks for using Syncfusion products.
You can configured required framework version controls in Visual Studio toolbox, please refer the below mentioned KB article to resolve the reported issue.
http://www.syncfusion.com/kb/2336
Syncfusion controls does not support Visual Studio Express Edition toolbox. But, we can manually configure Syncfusion controls in Visual Studio Express Edition toolbox. Please refer the below Knowledge Base link for toolbox manual configuration.
http://www.syncfusion.com/kb/2328
If you still face the issue, in order to check the issue please follow the steps suggested in the following Knowledge Base article link and send us the zip file generated by our tool.
http://www.syncfusion.com/support/kb/2331
Please let us know, if you have any queries.
Regards,
Sivaguru S