It is usually best to avoid sharing a Firefox profile folder among different operating systems as this can lead to issues because some prefs store path to files and the file system on Linux is entirely different than what Windows uses.

Can you save the images that you see on a web page via "Tools > Page Info > Media"?

Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Thanks cor-el,

Thanks to the link you posted i manage to solve my problem. It seems that content-prefs.sqlite was the problem. I open it in sqlite browser had a look at it and found some strange paths in prefs table (related to browser.upload.lastDir). after deleting them i was able to save images

The last used directory for the website (host) serving the file for download will be preselected in the file picker.

If no download directory for the current website (host) has been stored, browser.download.lastDir will be used.

You can disable this feature to remember a host based download directory by creating a new Boolean pref on the about:config page with the name browser.download.lastDir.savePerSite pref and set its value to false.

• https://developer.mozilla.org/Mozilla/Preferences/Preference_reference/browser.download.lastDir.savePerSite

well the funny part is that is not about the download. the paths were wrong for browser.upload.lastDir

Edit: there is no browser.download.lastDir.savePerSite entry in about:config. only browser.download.lastDir

The browser.download.lastDir.savePerSite pref doesn't exist by default. If you want to use a setting of this pref that isn't the default then you need to create this pref as a new Boolean pref like I wrote above.

well ive tried that pref entry right now...good thing that i still had that content-prefs.sqlite around. it turns out that that pref its not solving the saving issue. well...whatever....the problem is solved. im still confuse why i couldnt save the file since the problem was related to browser.upload.lastDir.... probably firefox has a bug with some characters/encoding in sql tables....

The pref prevents saving the download folder in the content-prefs.sqlite file. If there are already such download entries in the content-prefs.sqlite file then those won't be affected and will likely still have effect, so you would still have to delete this file of purge entries otherwise. So creating this pres is merely for future prevention.

Did you create separate profiles for each OS?

nope. im still using the same old profile that i share between os. so far i have no more problems. i think the problem was with the folder that use to be in utf-8 (jp chars) and somehow got messed up in db.