Why can't I start the copter simulator? Unexpected character encountered while parsing... etc

[seattleiteFPV]

I am using Mission Planner 1.3.7563. I am trying to launch the Simulator and getting this error… Any thoughts? Am I doing something wrong?

[Eosbandi (Andras Schaffer)]

Read my lips : Get latest beta.

[seattleiteFPV]

Latest Beta seems to work. Thank you.