Browser hangs when a screen is empty with no appropriate message in the logs

In JIRA 5.1.1, if you make the following steps:

1. Create an empty Screen.
2. Add it to a Screen Scheme and map it to an Issue Operation (e.g. Edit Issue)
3. Associate that Screen Scheme with a Project.
4. Create a ticket and try to Edit it.

The result is that your browser hangs while you do not get a relevant message in the logs.

Resolution is to add at least one field in that screen.

Can we please check

1. Why does the browser hang?
2. How we can add an informative message in the logs instead of having the browser loading indefinitely?

We have reproduced and created this KB about this.

Thanks.