Cannot read property 'toLowerCase' of undefined

I am just checking out Wappler and tried one simple thing:

• Create a new project from the Mobile Template
• Added iOS 4.5.5 from the Platform menu
• Clicked ‘Run’

A system check was performed successfully and then I get this message:

Building your Cordova Project for ios ...
Cannot read property 'toLowerCase' of undefined
Error building your Cordova Project for ios!

If I open the project in XCode it builds just fine…

Any hint?