There is a red "X" in the Navigation Pane or in the credential list.
There are a few things you can try to get rid of the red X.
First, try going to the Window tab and click Reset Layout
Sometimes that can fix some red X issues.
If that does not work, you can try to close Remote Desktop Manager, then navigate to %localappdata%\Devolutions\RemoteDesktopManager and delete every file with thelyt extension.
If neither of those methods does the trick, you will have to move the RemoteDesktopManager folder from localappdata to your desktop, then uninstall Remote Desktop Manager, reboot your computer and reinstall Remote Desktop Manager. Once you reopen Remote Desktop Manager, the red X should be gone.Feedback