Please explain the problem in detail. What happens? What is/are the exact error message(s) ?

Make sure you are not blocking content.

Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

Many site issues can be caused by corrupt cookies or cache.

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Delete cookies to remove the information websites have stored on your computer {web link}

• How to clear the Firefox cache {web link}acking-protection-firefox-desktop

I started Firefox in Safe Mode and it did not solve the problem. When I generate a report, the report will not display on my screen, I can only access it through the download arrow in the upper right corner.

What kind of reports are that ? Is this about PDF files ?

Just regular software generated reports. e.g. payroll reports from a payroll software program, tax returns from an efile software provider. They are not pdf files.

Sounds that this is a file type that Firefox doesn't support.

What kind of file do you get when you download the file and what application can handle this file ?

I have been using Firefox for years and did not have this problem. The issue just started last weekend.

When you download the files, are they Excel (.xls, .xlsx) files? What format are they?

I'm sorry - they are a PDF report when downloaded.

Firefox should be able to open PDF files that aren't send as "application/pdf", but are send as "application/octet-stream" or "content-disposition:attachment" in a tab by selecting "Open in Firefox" in the download dialog.

Don't you get this "Open in Firefox" choice ?

What does the Network Monitor or Browser Console (XHR, Requests) show about the server response of this download ?

• https://developer.mozilla.org/en-US/docs/Tools/Network_Monitor
• https://developer.mozilla.org/en-US/docs/Tools/Browser_Console

Good news. We went into Firefox Options/Application/PDF and it show "Save File" to "Open in Firefox" and it worked. FYI it worked prior to Firefox Update 85.02 on 2/10/21.

Thanks for all of your help.

That was very good work. Well Done.