Can you check your exact version of Sitefinity? To do so, go to your project's bin folder and locate the Telerik.Sitefinity.dll. Right-click it, choose Properties and then select the Details tab. You can see the version in the File version field.
Additionally, try to restart the application by making a dummy change and saving your project's web.config file.
All the best,
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items