Hello, And if you try to open the file with the dedicated program? Open pdf in evince , images in the image viewer, etc What happens?

AnnaSycamore said

Hello, And if you try to open the file with the dedicated program? Open pdf in evince , images in the image viewer, etc What happens?

From file manager? of course it opens, the problem is just with Firefox.

Sounds like bad formatted file. So is that a file others can see what it is? And where are you getting that file from?

WestEnd said

Sounds like bad formatted file. So is that a file others can see what it is? And where are you getting that file from?

Wherever I get it from, it happens with all the files, images, pdf, videos, from every webpage.

You said "in the Firefox downloads menu, it shows a pop-up that says the file is executable" But you are on Linux (It just happens on my Linux partition, ) There is no standard File-Extention like an ".exe" file in Windows. On Linux you can make files, you can execute scripts but executable .... You run firefox on wine? Try to run Firefox native app https://support.mozilla.org/en-US/kb/install-firefox-linux

AnnaSycamore said

You said "in the Firefox downloads menu, it shows a pop-up that says the file is executable" But you are on Linux (It just happens on my Linux partition, ) There is no standard File-Extention like an ".exe" file in Windows. On Linux you can make files, you can execute scripts but executable .... You run firefox on wine? Try to run Firefox native app https://support.mozilla.org/en-US/kb/install-firefox-linux

I run the native app, so I don´t know what firefox refers to when talking about executable files.

When I do the same on Tor for example, I get the same message but after click "ok", the file opens, not like on firefox.

You download these files from the internet Try to change the Firefox action from Always ask to Save file Change what Firefox does when you click on or download a file

https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file

AnnaSycamore said

You download this files from the internet Try to change the Firefox action from Always ask to Save file Change what Firefox does when you click on or download a file https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file

It didn´t work, I get the same error. I also tried some configurations and tried to restart the browser profile and I get the same result.

What Linux distribution you have ? On Ubuntu Ubuntu based Try remove and then reinstall FF https://help.ubuntu.com/stable/ubuntu-help/addremove-remove.html.en

AnnaSycamore said

What Linux distribution you have ? On Ubuntu Ubuntu based Try remove and then reinstall FF https://help.ubuntu.com/stable/ubuntu-help/addremove-remove.html.en

I have Manjaro Linux. I didn´t try to reinstall but I don´t think it will help. Anyway I would like to solve this without reinstalling, I can´t lose some configurations and addons. If it is the only solution I will, but at this time I don´t think it will fix anything.

You can save the profile folder Or if you prefer try the official method reset/refresh FF and FF save the old data in a desktop folder

":Your old Firefox profile will be placed on your desktop in a folder named "Old Firefox Data". If the refresh didn't fix your problem you can restore some of the information not saved by copying files to the new profile that was created. If you don't need this folder any longer, you should delete it as it contains sensitive information."

https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

I found two other threads during the past year with a similar message, but no clear explanation:

(1) Why does firefox think .tif file is an executable? - Firefox 58 on MacOS 10.11, problem went away by itself

(2) Why does Firefox warm me that pdf is an executable file? - Firefox 57 on MacOS 10.12 - marked solved by two support articles without indicating the specific way it was solved

You can use a command like this in a terminal window to query the default application and set the default application of a specific content type.

• MIME type:
  xdg-mime query default application/pdf
• File extension:
  xdg-mime query filetype *.pdf

• Set default application for a MIME type:
• xdg-mime default evince-2.desktop application/pdf

Hello,

You modify profiles and configurations and you have a dual-boot machine.

I think the best solution in this case is the clean install of Firefox You can use FEBE add-on for a complete backup of your Firefox;

A little about it : Customizing FF on Manjaro 

https://wiki.manjaro.org/index.php/Firefox_Customisation

Install and remove a program on Manjaro

https://itsfoss.com/install-remove-software-manjaro/

Hope this help Have a nice Sunday

AnnaSycamore said

Hello, You modify profiles and configurations and you have a dual-boot machine. I think the best solution in this case is the clean install of Firefox You can use FEBE add-on for a complete backup of your Firefox; A little about it : Customizing FF on Manjaro https://wiki.manjaro.org/index.php/Firefox_Customisation Install and remove a program on Manjaro https://itsfoss.com/install-remove-software-manjaro/ Hope this help Have a nice Sunday

I did it, I removed all the files and uninstalled all of Firefox from my system, but after reinstall it the problem still here. I´m using the new installation right now and indeed the issue is the same. I don´t know what to do now.

What file extensions do the files have or isn't there a file extension at all (i.e. just a name part)?

Did you check the MIME cache (mimeapps.list and mimeinfo.cache)?

cor-el said

What file extensions do the files have or isn't there a file extension at all (i.e. just a name part)? Did you check the MIME cache (mimeapps.list and mimeinfo.cache)?

The file extension is jpg/png or any image, but it happens also with other extensions like pdf. And how do I check mime files? what is the location?

See e.g.:

• https://wiki.archlinux.org/index.php/XDG_MIME_Applications

cor-el said

See e.g.:

• https://wiki.archlinux.org/index.php/XDG_MIME_Applications

But my problem is only with Firefox, so the problem is Firefox, not the OS.