After a lot of searching and grabbing bits of the whole solution from different sites and personally testing them, i finally figured out how to solve this widespread problem.

It's a very simple problem actually. Firefox cannot load any PDF file in the browser window, simply because the FoxitreaderOCX.ocx file is missing! What you need to do, is to restore that missing ocx file to its correct path on your computer. I am using only Foxit PantomPDF and Firefox 5.0 final. Foxit Reader is not installed on my Windows as it might create conflicts with PhantomPDF since the former is basically a component of Foxit PhantomPDF.

Before we begin any tinkering with your Windows system, you should make sure that you are using the latest version of Foxit Reader or Foxit PhantomPDF, and also update your Firefox to the latest version. After updating, open Firefox and from the top menu: Tools > Add-ons, click on "Plugins" on the left side to verify that "Foxit Plugin Reader for Mozilla" is listed. Make sure that the plugin is enabled. If you are using Foxit Reader, then you can just skip to the before-last paragraph.

What i did to resolve my problem is to create this path: C:\Program Files\Foxit Software\Foxit Reader\plugins\FoxitReaderOCX.ocx Note that i don't have Foxit Reader installed, as Foxit PhantomPDF already does all of that and even more! But even without Foxit Reader installed, the path is required. So, create the folders in the exact same order.

I simply copied the original FoxitReaderOCX.ocx file from the plugins folder found at this path: C:\Program Files\Foxit Software\foxit phantom\plugins And then i pasted the file to the newly created path (just create folders with the exact file names and place the FoxitReaderOCX.ocx file in there).

Now, to check if everything is in order, you can do this: Run Windows with Admin privileges account, and do one of the following steps

1. Navigate to Foxit Reader install directory (like “C:\Program Files\Foxit Software\Foxit Reader”), right click on Foxit Reader and select Run as Admin.

2. Click Start, select Run, in the Open line, input "regsvr32.exe "C:\Program Files\Foxit Software\Foxit Reader\plugins\FoxitReaderOCX.ocx"". You shall get a success message if succeeded. Note: the ocx file path depends on where you install Foxit Reader

3. If you are prompted "no administrator rights", please browse to Start->All Programs->Accessories->Command Prompt, select "Run as administrator" by right clicking on it, then repeat the step2 above.

If you get a success message, then you have done all of the copy-paste and new path creation correctly. Then you just have to go to Firefox menu. Tools > Options > Applications and scroll down the list until you see "PDF Document" on the left side. Right next to it, click on the list and make sure that this option is selected "Use Foxit Reader Plugin for Mozilla". Finally, press OK to confirm and this should guarantee that all PDF files will now open inside your Firefox window. You can try it and it should work.

I hope that this helps all of you having the same problem as i did. I was stuck with this issue for a very long time, several months, but then i got fed up and decided to do some research on how to fix this once and for all. Feel free to share this solution on other sites but please give credit to me (shaksnet) for writing this help guide. Thank you!

well, foxit has been of no help...so maybe mozilla support can! thanks for your post, but i'm a little confused about some of what you did. you said that you don't have foxit reader installed because of a possible conflict with foxit phantom that you do have installed. you said that you got Foxit"Reader"OCX.ocx from the "phantom" plugins folder. maybe there's something wrong with my phantom install. i don't have the "reader" ocx file in the plugins folder of the phantom. i do have the "phantom" ocx file. like you, i Uninstalled foxit reader, creator and editor AND ALL assoc. files including the plugins. i mean, i had nothing left in the program files, start menu, app data files, firefox addons and registry. this is probably more of an issue for foxit, but i thought i'd write anyway. so, after the phantom install, which went smooth, i got the phantom plugin for mozilla as expected and the phantom ocx file in the phantom directory plugins folder, but not reader ocx file. i do have a side problem and i'm sure it's related. the setting in the phantom preferences, "display pdf in browser" doesn't stay checked, no matter what i do. like i said, i've been working with foxit, so i'll send this note on and see what happens.

Opening PDF files within Firefox

https://support.mozilla.com/en-US/kb/Opening%20PDF%20files%20within%20Firefox

Check and tell if its working.

Replying to mha007: Your link to help with opening PDF docs in Firefox is only good if you want to use an Adobe plugin. It doesn't help if you want to use a Foxit plugin.

Replying to shaksnet: It was your post that helped the most. Although it was unclear to me as to the exact procedure of what you did. So, I did a little work on my own, since Foxit support was not helping. First, I Uninstalled everything Foxit. Then, I downloaded the latest versions of Foxit Reader and Phantom. Next, I installed Foxit Reader. Then, navigated to the Foxit Reader Program Files and found the FoxitReaderOCX.ocx file in the Plugins Folder. I Copied that file to my Desktop, then Uninstalled Foxit Reader. Next, I Installed Foxit Phantom. Just like shaksnet said, you must create a folder for the FoxitReaderOCX.ocx file to reside in. So, I moved the FoxitReaderOCX.ocx file from my Desktop to a folder called "plugins". I put that folder in another folder called "Foxit Reader". In the final installation, this is what I have: Foxit Phantom is installed here: C:\Program Files\Foxit Software\Foxit PhantomPDF and the FoxitReaderOCX.ocx file is here: C:\Program Files\Foxit Software\Foxit Reader\plugins. As for Firefox, the only Plugin that is installed for viewing PDF docs in the browser is Foxit PhantomPDF Plugin for Mozilla. You will notice that when you install Foxit Reader to copy the FoxitReaderOCX.ocx file, the Foxit Reader Plugin for Mozilla is installed. But that plugin is Uninstalled when you Uninstall Foxit Reader. Likewise, when you install Foxit Phantom, the plugin for Foxit Phantom is installed. So, when done, the only Foxit Plugin I have installed in Firefox is Foxit PhantomPDF Plugin for Mozilla. Also, if you go to Firefox Tools>Options>Applications and scroll down to PDF Document on the left side, the corresponding Action will be "Use Foxit Reader Plugin" when you have Foxit Reader installed and "Use Foxit Phantom Plugin" when you have Foxit Phantom installed. What I don't understand is why the installation of the Foxit Phantom didn't create the FoxitReaderOCX.ocx file in the Foxit Reader\plugins folder! And why does this even work, since there is a FoxitPhantomPDFOCX.ocx file in the Foxit PhantomPDF\plugins folder! I have been trying to register this file, but that just gives me an error message: "LoadLibrary("C:\Program") failed. The specified module could not be found." I have no idea what that means. Bottom line...this fix seems to have solved my problem of not being able to view PDF docs in Firefox. Also, the setting "Display PDF in Browser" in the Foxit Phantom File Association Preferences stays checked. Thanks, shaksnet, for starting me on the path to finding the solution.

One last thing that I forgot...I had to register the FoxitReaderOCX.ocx file since Uninstalling Foxit Reader Unregistered it. I'll paraphrase from shaksnet: Click Start>Run. In the Open line, type or copy and paste this exact line: regsvr32.exe "C:\Program Files\Foxit Software\Foxit Reader\plugins\FoxitReaderOCX.ocx" You should get a message something like this: DllRegisterServer in C:\Program Files\Foxit Software\Foxit Reader\plugins\FoxitReaderOCX.ocx succeeded. Of course, if the Foxit Reader folder has been put in a different location, then the path entered in the Open line should be changed to that location. And all of this should be done using an administrator account user.