Remote Desktop Manager does not open after the splash screen.
This is due to an issue with the Remote Desktop Manager configuration file. The file is located in %localappdata%\Devolutions\RemoteDesktopManager and is called RemoteDesktopManager.cfg.
You will need to move this file and reopen Remote Desktop Manager, it will create a brand new configuration file.
You will have to re-register all of your data sources and point to either the file or database that you were using.