Does this affect particular websites or types of documents? For example:

• Email attachments
• docx and pdf files

Et cetera. Any kind of information about the pattern would be helpful.

Also, do you have Firefox set to ask you where to save files? And if so, does it matter whether you save the file into your own Windows profile folders (e.g., Downloads or Documents) vs. other folders (e.g., F:\Stuff)? You can set the download behavior under:

"3-bar" menu button (or Tools menu) > Options > General

(See: Startup, home page, tabs, and download settings)

Note that your System Details list shows that you have a user.js file in the profile folder to initialize prefs each time Firefox starts. The user.js file is only present if you or other software has created this file and normally it wouldn't be there.

You can check its content with a plain text editor (right-click: "Open with"; do not double-click). The user.js file is read each time Firefox is started and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

You can delete the user.js file if you didn't create this file yourself.

• http://kb.mozillazine.org/Preferences_not_saved

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I tried with all the file that i think of (.docx, .rar, .7z)

The save file is located on my d:/ drive but even with that, firefox send all the file that i try to download and open directly with a software to the window temporary folder with the read-only option.

That's true, if you choose Open instead of Save, then Firefox uses the Windows TEMP folder. I'm not sure why a file in the TEMP folder would be read only. Maybe to avoid the problem that a user might open a file, save a change, and end up saving it in a location vulnerable to being cleared out??

Okay, yes, this appears to be a change to return Firefox to the way it worked in Firefox 25 and earlier (it was unintentional that the file was not marked read only in Firefox 26-37).

When you launch a download direct in an application, the file is marked read-only because Firefox normally removes these files at some point, and this protects users against losing changes to the file. (Bugs #1022816, #1009465)

But the application you're using to open the file won't open a read-only file at all? So this is a definite problem in your case. Hmm...

it's not able to import the file because he copy it to it local folder and remove the file from the download directory, so he cant remove/transfer it :S

Btw, like i said, i have a custom directory for my download so the file don't go in a temp folder that got wiped out every time i close Firefox...

There is no way we can choose where to really download the file like before ?

Only is you open a file directly in another application then the file is downloaded to the TEMP folder. If you download and save the file then you can choose the location.