You can look at the latest version of the PDF Viewer (pdfjs) extension to see if that works better (still can't fill forms).

• PDF Viewer: https://addons.mozilla.org/firefox/addon/pdfjs/

Did you check the setting for Portable Document Format in Tools > Options > Applications ?

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

Did the suggestion above(Add-on),It changed NOTHING.It did as if downloading the paper I intended originally.After that a white page appeared and shortly after even the sign at the upper part(Print,etc.)have disappeared and the white page was left.I NEVER EVER had this problem before,reading issues of the same journal every two weeks or so!Thanks Firefox!!!!What I don't understand is,that so often new things are introduced,when they are not necessary.Haven't you heard:if it aint broke,dont fix it??!!Sad!!!!!!!!!

Current Firefox versions have enabled a new build-in PDF Viewer and that viewer doesn't have all the features that the Adobe Reader has.

You can change the action for Portable Document Format (PDF) from Preview in Firefox to use the Adobe Reader or set to Always Ask in "Firefox > Options > Applications".

You can set the pdfjs.disabled pref to true on the about:config page to disable the build-in PDF viewer and use the Adobe Reader instead.

See also:

• https://support.mozilla.org/kb/view-pdf-files-firefox-without-downloading-them

Went to Applications,and marked Foxit to open PDF-s.It doesn't work automatically.The same white page comes up(as before).If I keep double clicking time after time on the white page,Foxit downloads the file and it does appear finally.But it is not automatic. Basically,the fact remains.Wheras I never had any problem with this regular journal,now I do.Thanks to Firefox insisting on fixing and issue that definitely wasn't "broke".The question remains:WHY???????????