Thank you for your post.
I am unable to replicate the problem with FileMaker Pro 12.0v1 on an iMac running Mac OS X 10.7.3. When I use a New Window script step and set the Window Style to "Dialog window (modal)" with only the "Close" option checked, a new window opens with only the "Close" button available.
Is it possible you have a script trigger that activates when the record is loaded in the new window?
Any other information you can provide to help me replicate the problem would be helpful.
I think I have found more specific information on the issue.
Create a container and put it on the layout as interactive field
Load a pdf into it
Then the behaviour is exhibited, if there is no file in there it is not.
Thank you for the specifics. I can definitely reproduce the problem on Mac OS X 10.7.3. This works as expected on Windows (XP SP3).
I have sent your posts along with my findings to our Development and Testing departments for review. I will keep you updated as information becomes available to me.