LockDown Browser will not open if it detects Google Remote Desktop on the computer.

There may be a plugin in either Google Chrome or Internet Explorer that is keeping a component of Google Remote Desktop actively running in the background.
You will most likely need to remove the Google Remote Desktop from your computer.

Details on removing the add-on can be found at Google Support here: https://support.google.com/chrome/answer/1649523?hl=en
 
A. Remove Chrome Remote Desktop app from Chrome

If you’re signed in to Chrome on multiple computers and choose to remove the Chrome Remote Desktop app, you will remove it from all the computers you are signed in to.

    Type "chrome://extensions" into the address bar.
    Find "Chrome Remote Desktop" and click the trash can icon Remove an extension from Chrome
    A confirmation dialog appears, click Remove.

B. Remove Chrome Remote Desktop application from your computer

If you have enabled remote connections on this computer, you’ll need to remove the Chrome Remote desktop application from your computer as well.
 Windows:
    Go to Control Panel > Programs > Add/Remove Programs.
    Find "Chrome Remote Desktop" application.
    Click Remove.

Mac:
    
    Find the "Chrome Remote Desktop Host Uninstaller" application.
    Launch the uninstaller and click “Uninstall.”