Universal theme
APEX 5.1.1
Chrome 58
I have page with the following data on it. If I leave it as a normal page and navigate to it from a dynamic navigation bar entry (URL Stored in Database table) "f?p=UA5:5:&SESSION.:CHANGE_APP:&DEBUG.:5::" it works fine.

If I turn the change password page into a Modal Dialog I get a blank dialog box:

Any ideas on why the page won't display as a modal dialog?
It also comes up blank if its set to a non-modal dialog.

thanks in advance
PaulP