I would like to add to the above question that the extension on the files I am trying to view, but not download, is aspx. I don't know if that is relevant information. When I do go ahead and download, that extension is shown, not pdf.

This is a new problem. I have viewed these same type files hundreds of times with no issues.

Thanks very much.

I just looked at your two posts. Thank you for the second one, as it makes your situation a lot clearer.

It looks like the problem that you are having may not be directly involving Firefox, rather it is a problem with the website that you are using. Basically, you should not be presented with an aspx file (an Active Server Page Extended file that's designed for Microsoft's ASP.NET framework), but rather a proper user file type like PDF. Please look at the information on ASPX file here:

https://www.lifewire.com/what-is-an-aspx-file-2619705

You will see from the information there that if the file should have been a PDF, you can download it and rename the extension from .aspx to .pdf, then load it in Acrobat or another PDF reader (or Firefox).

To check how Firefox on your system is set to hand PDF files, look at Options -> General -> Applications where you will see a list of file types. Alongside "Portable Document Format (PDF)" you will see your current Firefox action (which you can change via the drop-down list at the right).

In my case, I am the opposite of yourself in that I do not want to preview a PDF in Firefox, but rather save it and open the saved file in Acrobat, so I have "Save File" set at the action. In your case, you would need to set "Preview in Firefox" (which I think it the default action anyway).

Unfortunately, that will not help you preview an aspx file, and you would still need to download it and either rename the file extension or use "Open with" and Acrobat (or another reader).

Hope this helps?

Hello Richard and thank you so much for trying to assist me.

I read the link you sent on aspx files -- and learned from it. But the site, with regard to aspx files, says "There's no need to do anything to open this type of file because your browser does it for you, whether it's Chrome, Firefox, Internet Explorer, etc." So it seemed like they were saying my browser should not have this problem.

What I am trying to open are legal statutes. I have viewed hundreds of them, using Firefox, and in the past when I clicked on the link, it just opens the statute. Then suddenly, I started getting a window instead which only gives me the opportunity to save the file. IN THAT WINDOW, it shows it as an aspx file. When I use Safari, and click on the link, the statute quickly opens like it used to in Firefox. So since Safari opens the statute, it doesn't seem like it is the website. Seems like it is a Firefox glitch.

When I go to Options > General > Applications and click the drop down menu, it does not give me the option to click "Preview in Firefox." I feel like that is the problem. But I don't know how to fix it.

Any other thoughts would be appreciated.

Hi Subak. Thank you for your additional information. I think you have identified the root of the problem here:

When I go to Options > General > Applications and click the drop down menu, it does not give me the option to click "Preview in Firefox." I feel like that is the problem. But I don't know how to fix it.

I have been doing some research to see if there was an easy way to add additional file types. The Mozilla info is here:

https://support.mozilla.org/en-US/kb/applications-panel-set-how-firefox-h...

At the bottom of the page it has a heading "Add or remove a file type", but it includes this sentence:

You can change the action for an existing file type but you cannot add or remove file types.

So, it looks like there is no easy mechanism to be able to set up how an aspx file is handled. Unfortunately, I personally do not know how to work around that, but maybe one of the other contributors here might know something that I don't and be able to help you?

Sorry. Richard.

Richard, you are a gentleman and a scholar. Many thanks for your time devoted to solving another's problems. I will persevere and hope another Firefox loyalist has some suggestions.

Subak

Hi again Subak.

Thank you for your kind compliments! I am a noob contributor on here, just trying my best to help people with issues that I feel able to give some helpful advice on. Sometimes, as in your case, the problem turns out to be something that I do not know a definite answer to.

Installing Official Adobe Acrobat Reader

I contacted one of the experienced contributors (who is also a moderator) about your issue and he advised me to request that you try installing the Adobe Acrobat Reader program, rather than just relying on the built-in Firefox ability to handle the file types. As he put it:

...as the browser plugin may help open that file directly. The .pdf viewer in Firefox is good, but may struggle with some of those more extreme file types.

The general download link is:

https://get.adobe.com/reader/

Note: I advise being careful on the download though, as Adobe (very annoyingly to me) adds other McAfee stuff (unwanted by me) to the download by default, so I always de-select that before clicking the button.

An Add-on Extension that might help...

I did also find another Add-on that might help too. It is called "Open With Adobe PDF Reader" and you can see it here:

https://addons.mozilla.org/en-GB/fire.../open-with-adobe-pdf-reader/

From its description:

This extension adds a context menu item to your browser context menu over PDF links. When the context menu is clicked, the extension downloads PDF file into your default download directory and then executes external application to open this PDF file.

What is not actually clear to me is whether you can select a link to ANY file type (e.g. your aspx file type) to send to the Adobe Acrobat Reader, if so, you could be onto a winner, except that by its nature you would actually downloading the file to view it, as such, even if not by the normal download mechanism.

Summary

So in summary:

• (1) If you could download and install the official Adobe Acrobat Reader program first and see if that helps Firefox to handle your files.

• (2) If you are still having a problem, try installing the "Open With Adobe PDF Reader" extension and testing.

• (3) Provide some feedback on your testing so that we can escalate the issue with good information. The reason that I think that it should be escalated is in your original question, you clearly stated that it worked before, but does not now (if you can remember the last version of Firefox that it worked in without any plugin added, that would be great too).

This is a new problem. I have viewed these same type files hundreds of times with no issues.

Thanks, Richard.

Hello again Richard!! Sorry I am tardy replying to you...

I have Adobe and use it regularly. When I go to Options > General > Applications and click the drop down menu, it gives me the option to open files with Adobe. I have chosen that option, but still I can only Save files, not open and read, when Firefox is set to use Adobe to open.

I installed Open With Adobe PDF Reader as you suggested and tried again, but still no change.

Since this problem developed a few days ago, I have been experimenting with other PDF files. Anytime I am on a site and it refers me to a PDF, and I click on it, I get the same window telling me I can only Save. And those files are showing the .pdf extension. In other words, the glitch still occurs when the extension is .pdf, not ,aspx.

I am still hung up on why the drop down menu that gives the options for how you want to open files, does not give me the option to click "Preview in Firefox." As I understand it, that should be showing up as an option. The fellow that you contacted on my behalf (thank you), in suggesting Adobe, talked about the Firefox built-in may not be able to handle some files. I can't seem to use the Firefox built in. I don't get the option to "Preview in Firefox." Also, now we know we are talking about just regular .pdf files, not files with .aspx.

I have started using Safari whenever I need to read a pdf and don't like it as well as Firefox. I am really stumped on this. If you have any other ideas, I am all ears. Thanks for your time...Subak

Hi Subak

The plot thickens :)

Although I normally download PDFs and view them in Acrobat Reader, I just changed the setting for those file types and found a test.pdf file under Google search and opened it successfully in a new browser tab (see attached images).

When I click the Action down arrow, the options that I can select are:

• Preview in Firefox
• Always ask
• Save File
• Use Adobe Acrobat Reader DC (def...
• Use other...

You said:

I am still hung up on why the drop down menu that gives the options for how you want to open files, does not give me the option to click "Preview in Firefox." As I understand it, that should be showing up as an option.

I just found an old support question for someone raising that problem and it was due to them looking at the actions for "PDF File" rather than "Portable Document Format (PDF)", so I wonder if that is what you are doing too?

https://support.mozilla.org/en-US/que.../1176268

Please let us know how you get on... Richard.

YES!!!!!!!!!!

That was it Richard. I was going to PDF, not Portable Document Format. When I use Portable Document Format, it gives me the Option to "Preview with Firefox." (However, that does not work.) But when I use Adobe in that drop down menu, it works like it used to.

The setting in that drop down menu was set to "Save." That's why!!!! I don't know how it got switched to Save but you solved it for me!!!!

I hope you can get a lot of satisfaction out of resolving this mystery and help a fellow human being. I am extremely grateful for your diligence.

Thank you Richard!!!!!

Great stuff. Please mark this as solved. Thank you, Richard.

Just a pop-in to give props to Richard. You really went out of your way to investigate this issue, and it helped solve my problem, too. Only very recently, FF had begun to refuse to preview .pdf files, rendering them in a new tab only as empty .aspx pages. When downloading the file, it would download as .aspx, not as .pdf. Weird. I had to jump over to Edge to get my hands on the .pdf file.

I wonder if the applications settings in the FF options menu got scrambled by any of the add-ons I have loaded. I have some pretty tight privacy/security add-ons, including Cookie AutoDelete, and I wonder if it might be a factor here.

Anyway, issue solved for now. Thanks for your willingness to help.