Alert message div blocked some menu bar dropdown buttons

[JinXJinX]

Expected Behavior

Alert message should not block partial menu bar dropdown buttons.

Actual Behavior

menu bar dropdown buttons are blocked by alert message div

Steps to Reproduce

1. trigger a alert message
2. click 'file' button in menu bar
3. you can see 'new' button and 'load from computer' button is covered by alert's div

Explain what someone needs to do in order to see what's described in Actual behavior above

Operating System and Browser

Mac OS 10.14.2 Safari 12.0.2/ Chrome 71.0.3578/ FireFox 64.0.2

[thisandagain]

@carljbowman Any thoughts on the desired z-index here? I can see arguments both ways.

[carljbowman]

Seeing this, I lean towards z-indexing the nav and nav menus above alerts. Since alerts sometimes prompt using the file menu: for example if you lose an internet connection we prompt you to download your project. We do provide a download button in this specific alert example, but I could see people attempting to use the File > Menu to try to reinitiate a save or download to computer.

It's also a bit awkward that alerts could potentially block "Undo" & "Redo" in the Edit menu.

All that said, I am open to other thoughts as to why we should keep the current z-indexing or alerts above nav and nav menus.

[thisandagain]

Thanks @carljbowman. Sounds good.

[thisandagain]

/cc @chrisgarrity Another z-index issue if you'd like to add this one to your backlog.

[benjiwheeler]

Related to #4226

[benjiwheeler]

From my checking, it appears this issue was already fixed before #4916 went in. Possibly it was fixed by #4452.

[apple502j]

@benjiwheeler Not for me on Firefox 76:

1. On sound tab, upload non-sounds (this creates an alert that cannot disappear)
2. You cannot click Code/Costume tab
3. On develop you can

[benjiwheeler]

@apple502j I totally agree about the Code/Costume tabs. But this issue is about menu bar dropdown menus.