Issues in Binding Editor for user added properties

Binding Editor doesn't seem to work correctly for user added properties. Tested with the latest snapshot of 3.7.0. Steps:

• Create/open a project
• Add new property for e.g. root rectangle
• give it a name and select type "color"
• Select action icon and choose -> set binding
• -> In Binding Editor you can see warning "rectangle.newproperty: Property does not exist"
• Try adding a value, e.g. #4aee45 and click OK
• -> "Error rewriting document" is seen
• Click Ok
• Click Cancel
• -> Binding Editor does not close