Thank you for your post!
You might just make the container a Button, depending on if they will need to do much with it after the file is inserted.
You could also overlay a transparent button so that it looks like they click the container and are able to Insert File. You might have the Button Hide after a file is inserted so they can interact with the Container without issue.
Attached is a sample of these two methods.
I am also going to move this thread from the FileMaker Community Feedback Space, which is specifically for input on the Community itself, to the Discussions Space where you should receive more views and potentially more (and better) feedback on this topic!
InsertContainer.fmp12.zip 67.3 K
Thank you! I knew it would be easy, had tried a button but forgot the hide step.