Firefox throws Javascript error

[jwkuehne]

1) In Firefox, clicking in the application and then accidentally releasing outside the application usually results in "Exception thrown" and the application freezes. This does not happen in Safari, Edge, or Chrome. How can I fix this for Firefox?

2) In all four browsers, if I click on the application the second it appears, especially with multiple clicks, it will likely malfunction or freeze. If I hide my control_panel group and wait three seconds - which is what I'm doing now - that solves the problem. This might be related to problem 1) above.

However, if I hide the control_panel group and then show a spinner, I'm back to freeze! I'm pretty that if I just disable the control_panel group during startup it will freeze from early mouse clicks.

Ideally customers shouldn't be madly clicking or releasing the mouse outside the app, either during startup or in operation, but they will.

Looking for some way to keep my app freezing from errant mousing in Firefox once it's going. That might give me a hint about how to deal with freezing when I hide the control group but show a spinner while the user is trying out a few clicks during startup.

Here's the app HJST CALCULATOR on my page http://drw.austin.utexas.edu where you can try it with Firefox: enter Sun (or Moon or any planet or format given in the text) on the first line, then click on the line, and you'll get the sun's position. However, if you click on Sun and release the mouse on the URL bar, it's a Javascript exception.

-John