1. Stop Desktop Central Server service (Services.msc or Start -> Programs -> ManageEngine Desktop Central -> Stop Desktop Central)
2. Delete the folders under "localhost" (%Program Files%\DesktopCentral_Server\work\Catalina\localhost)
3. Start the Desktop Central Server service(Services.msc or Start->Programs->ManageEngine Desktop Central->Start Desktop Central)
4. Open a new browser and open the Desktop Central web console to check the exception message occurs.
5. Please clear the browser cache to complete the process.