Sorry but we are not able to provide this at the moment One of parameters (value: ) is not of the type Integer

I'm not which version is running in the sandbox, all it says is 4.1 alpha so I may not have selected the correct version above.
I create an event, select free online registration, select conference, leave all defaults, click include map to event location, event location, use existing, Connecticut address, save
screen appears:
Sorry but we are not able to provide this at the moment.
One of parameters (value: ) is not of the type Integer
Return to home page.