Windows Defender may detect and block LogMeIn, but actually call it RemotelyAnywhere. This is Microsoft's definition and a name of another one of our products. It is safe to unblock it.
When you open Windows Defender, it will show a warning message that it has blocked a piece of software, and give you a link to click. This will take you to a listing, where you can select to Allow RemotelyAnywhere. This will prevent Windows Defender from blocking you from using LogMeIn.