You get tabs opening endlessly if you select Firefox as the application to handle a file when you get an "Open with" dialog.

• https://support.mozilla.org/en-US/kb/firefox-repeatedly-opens-empty-tabs-or-windows

You should never select Firefox as the application to handle a specific file type.

I did NOT choose Firefox to handle a file upon getting an "open with" dialog. Rather, as I said, I was trying to "download" a copy of a bill from, for example, Verizon. When I clicked "download", the endless tab parade began. The only way I could stop it was to click "close all tabs" which kept me from being able to download the file I wanted.

When I started all over on Chrome, I had no problem. Also, when I did the same procedure on my Mac, using Firefox, I had no problem.

Later in the day, I was on Fidelity on Firefox on my windows10 IOS, and the same issue happened again.

This never happened before today! The only thing I can make out is that the issue is with Firefox on Windows 10.

Any help will be appreciated.

What file extension does this file have?

It is likely that you had ever created such an automatic action for this file extension in the past.

You can check the handlers.json file in the profile folder and see if you can locate this file extension. If you aren't experienced with JSON files then best is to rename/remove handlers.json (handlersOLD.json) to reset all actions stored in the file. otherwise you can edit the file and remove this section and open the file in a Firefox tab to verify the file is still valid JSON code.

• https://developer.mozilla.org/en-US/Tools/JSON_viewer

I have never created an automatic action for "this file extension" and do not even know what file extension it may be.

Here are the steps leading to the problem: 1. I log in to the vendor - let's say Verizon 2. I click on "View Bill" which I do every month for several vendors 3. NORMALLY the bill opens and I save as a pdf. The address for the bill is NORMALLY something like: https://myvpostpay.verizonwireless.com/ui/bill/data/ao/printPdf?stmtDate=February+04,+2020

However, now I cannot get that far and cannot see the bill, because when I click "view bill" the tabs begin opening so fast I cannot see anything!

I have never used or even seen a handlers.json file.

If this is a PDF file then check this file type in Options/Preferences and make sure it is set to "Preview in Firefox" in case you have accidentally changed it to Firefox.

• Options/Preferences -> General -> Applications -> Portable Document Format (PDF)
• https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file

• https://support.mozilla.org/en-US/kb/view-pdf-files-firefox
• https://support.mozilla.org/en-US/kb/disable-built-pdf-viewer-and-use-another-viewer