After one presses the "Add" button in the Event wizard the dialog is empty, except for the buttons (all fields and labels have disappeared for entering the next event).
This happens on Mac OS X Yosemite with Rodin 3.1 and using the wizard from the structure editor.
I confirm the presence of this bug. Thank you very much for taking the time to report it.
Here is the attached stack trace:
Fixed in commit [1d4fbf]. Correction will be available in Rodin 3.2.
Related
Commit: [1d4fbf]