hi, try to go to the firefox menu ≡ > options > general panel & in the applications panel set the default action for the portable document format to "preview in firefox".

philipp said

hi, try to go to the firefox menu ≡ > options > general panel & in the applications panel set the default action for the portable document format to "preview in firefox".

As my problem stated I set the PDF Viewer set to Firefox a couple time and the problem continued

Thanks for the suggestion but as I wrote the PDF Viewer has been set to Firefox a couple time and the problem continues. Only works when Google Chrome is the default.

i was referring to the settings within firefox - not on the level of the operating system

Please use the setting philipp suggested ("Preview in PDF") if you want Firefox to be able to display PDFs in a tab. None of the other options do that.

Background: If you set up Firefox to open a file by using an application -- in this case Firefox -- that means to call up that external application. But this setting will apply again when Firefox receives the file from itself, triggering an endless loop of Firefox launching itself over and over and over. See: Firefox repeatedly opens empty tabs or windows after you click on a link.

Unless I'm missing something this is exactly what I've been doing. Firefox, Options, General, Application. See image

Hi speaalma, that looks good, but when you follow a link to a PDF, it launches in Chrome instead of in the tab?

The file used to store application handling preferences changed, so I don't know if it is still possible for it to become corrupted like the old one. You could remove it and see whether that helps:

Open your current Firefox settings (AKA Firefox profile) folder using 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, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename handlers.json to something like handlersOLD.json. If you see a file named mimeTypes.rdf, rename that one to mimeTypesOLD.rdf.

Start Firefox back up again. Does the default behavior return?

Thanks everyone for the feedback, however, the problem continued. I finally uninstalled and and then installed again and all is working fine.

Solved. I had the same issue. Had to CTRL ALT DEL and kill Firefox in Task Manager to stop it spawning new tabs. I didn't want to reinstall Firefox because I'd lose all my settings in my ad blocker and script blocker. I searched around a bit and came across the suggestion of restarting Firefox in Safe Mode. This disables add-ons and gives you the chance to enable/disable add-ons to see if one of them is the problem.

I restarted Firefox with all add-ons disabled <Menu - Help - Restart with Add-ons Disabled> and then opened a pdf I had saved. It opened fine so this told me it was an add-on problem. I re-enabled them one by one and found it to be the Google pdf viewer. I uninstalled it then restarted Firefox with all remaining add-ons enabled <Menu-Help-Restart Firefox with Add-ons Enabled>. All working fine now. When I select a pdf file it simply opens in a new tab.

I had previously tried deleting the handlers.json and it changed nothing. Also played around with the setting for handling pdf within Firefox <Menu-Options-Applications-Type pdf in the search box then choose an option from the dropdown list> but it changed nothing. Note: I left this set to "Preview in Firefox".

Hope this helps.

speaalma said

Thanks for the suggestion but as I wrote the PDF Viewer has been set to Firefox a couple time and the problem continues. Only works when Google Chrome is the default.

I had the same issue. Try Safe Mode to check if it's an add-on problem. This fixed it for me.