Hi LCKip, Thank you for your question, I understand that there is an issue looking at pdf files and that they turned into html files. Please check your application settings to see if the MIME type changedApplications panel - Set how Firefox handles different types of files

Use Troubleshoot Mode in Firefox If this is not the issue, can you please provide an example url for further investigation after troubleshooting your add ons.

Thank you and we look forward to your reply.

The settings in 'applications' are correct from the beginning. I didn't change them before or during installation of v. 31 and not after that too. What I described happened during installation and I corrected the situattion as I described afterwards. It's a completely waste of time to do any further investigation.

That is intentional and happens if there is currently no file handler application that handles PDF files.

• bug 452254 - Register for audio/video .ogg and .pdf file handlers if nothing else has

That is no solution! I'm NOT satisfied! However, I cannot use the green 'solved' key in your mail. I receive a message about some stupid technical error. Maybe you can mark my question as solved? Anyway, for me it's solved.

Sorry, but how did you fix it? Another user is looking for the solution in a different thread: https://support.mozilla.org/questions/1013576

OK, I'm definately DONE with this! I'm not willing to waste more time on this! When I receive an e-mail about this I am not allowed to click on the green button to close this case. Some technical error. Very sloppy. Therefore I will not respond to any further mail on this subject.

You already marked the thread solved before, but they stay open for some time before being archived. To discontinue email notifications, you can use the link to the right of your question, under "Question Tooks" => "Stop Email Updates"

This did happen on XP Pro 32 and 64 even when Foxit Reader is the default application for PDF's. I fixed this using this procedure. -Right click on any PDf file. -From the context options, go to "Open with" and click on "Choose program" -When the "Open With" window opens, select the program you want to use to open the pdf file. If it is installed but not listed, use the browse button. -Make this the default by clicking "Always use the selected program..." -Now click the "OK" button. All PDF's will now be opened with the program you selected. It is very rare that no PDF application is installed, but it does happen. In my opinion, the Firefox coders did a sloppy job with this version 31 update.

The relevant registry keys do not seem to be directly in HKEY_CLASSES_ROOT, but in HKLM or HKCU (SHCTX\SOFTWARE\Classes) I don't know if the registration is for all users (HKLM) or only for the current user (HKCU).

• http://mxr.mozilla.org/mozilla-release/source/browser/installer/windows/nsis/shared.nsh

451   ; Only add .pdf if it's not present
452   ${CheckIfRegistryKeyExists} "$0" ".pdf" $7
453   ${If} $7 == "false"
454     WriteRegStr SHCTX "$0\.pdf"  "" "FirefoxHTML"
455   ${EndIf}