When upgrading to Version 5.2 build 102, we have noticed that some users are having an issue with using the "Blank" slide in the Cue Editor. If you are in the Main Object and you drag it from the Stanza List below into the Play Order above, you get an error that says "The Parameter is Incorrect" and you can't get the error to go away. Our developers have been made aware of the issue and are working to push out a fix on this very quickly.
Simply update to the latest build by opening MediaShout->Help Menu->Check for Updates and that will resolve it for you. Thanks!