Hi markscheerer, what kind of links are you working with?

Usually if you click a link that the site has targeted to open in a new window or tab, as soon as Firefox determines that the content cannot be displayed in a tab and pops up the Open/Save/Cancel dialog, the blank tab closes automatically.

On the other hand, if you manually divert the link to a new tab (e.g., right-click > Open Link in New Tab, or middle click, or Command+click the link) the tab typically does not get closed automatically.

Refreshing only works until the next time I start up Firefox.

Unless you are installing an add-on during your session that changes how Firefox works in your next Firefox session, it could be...

Multiprocess (e10s)

One of the changes in Firefox 48+ is e10s, which separates the browser interface process from the page content process. More and more users are gradually having this multiprocess feature switched on. If your Firefox is compatible, it is enabled in your second session, so that would fit the pattern you describe. Let's check.

Are you using e10s?

You can confirm you have this feature turned on as follows. Either:

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, check the row for "Multiprocess Windows" and see whether the number on the left side of the fraction is greater than zero. If so, you are using e10s.

If you are using e10s:

If you think Firefox is not performing well or is using an unreasonable amount of resources now, you could evaluate whether e10s is causing this problem by turning it off as follows:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste autos and pause while the list is filtered

(3) Double-click the browser.tabs.remote.autostart.2 preference to switch the value from true to false

Note: the exact name of the preference may vary, but it will start with browser.tabs.remote.autostart

At your next Firefox startup, it should run in the traditional way. Any difference?

I am downloading mp3 files. The new blank tab opens up and the open/save dialogue box pops up. I choose "open with Quicktime player" and the blank tab DOES NOT go away. They accumulate along the top as I download and listen to each file.

The fraction at "multiprocess windows" is 1/1.

Markonehundred said

The fraction at "multiprocess windows" is 1/1.

Does it make any difference if you disable multiprocess?

Don't see how to do that. Next to 1/1 it says (enabled by default).

Markonehundred said

Don't see how to do that. Next to 1/1 it says (enabled by default).

Ah, that was covered by the last part of my earlier reply where you go into the about:config preferences editor.

That did the trick, apparently. Thank you!

Okay, there must be a bug with your combination of settings/add-ons. Not sure if it is a known problem already queued to be fixed or something new.

Someone might have some questions for you about how to reproduce the problem, especially if it's limited to certain sites and you were able to download media normally from other sites.