Unfortunately I wasn't able to reproduce the problem on my side.
What I could suggest is the following:
1. Open Windows Control Panel and go to Uninstall a program.
2. Search for Telerik Control Panel and if you have it installed, uninstall it.
3. Log in to your Telerik Account and from the first page which is opened after log in download the latest Telerik Control Panel.
3. Run the downloaded file and check if you could install or update any of our products.
Let me know if this helped.