error Firefox can't find the file at jar:file:///C:/Program Files (x86)/Mozilla Firefox/omni.ja!/

I have just upgraded to Firefox 15 and after I started using it, I got an error message on my screen saying jar:file:///C:/Program Files (x86)/Mozilla Firefox/omni.ja!/ was not found. I thought that there must have been some error while installing Firefox 15, so I uninstalled it and re-installed it again. But the problem continued to come on my screen. So I had the setup of Firefox 14 which I installed again and the problem was again seen. I mean before upgrading to Firefox 15, the Firefox 14 would work fine. Now even it has stopped working. Can someone tell me what the problem is?

This problem occurs when there is any interruption or disturbance while downloading the files of the Firefox. If while downloading it from internet, there was any breaking in the connection or the bandwidth had fluctuated at a good level, then the download must have been disturbed. The file that Firefox 15 is unable to find, which is jar:file:///C:/Program Files (x86)/Mozilla Firefox/omni.ja!/ must have been interrupted during download. You can try downloading Firefox 15 again. Also check if your anti-virus is not blocking the download of files of Firefox. Maybe it is recognizing it as malicious content and blocking it.

I think that it must be some add-on that you must have applied on Firefox 14 that is not allowing the Firefox15 to work properly. You must have installed some add-on that is compatible with Firefox 14 but not compatible with Firefox 15. Due to this when you are installing Firefox 15; the add-on must be restricting the activity of jar:file:///C:/Program Files (x86)/Mozilla Firefox/omni.ja!/. I suggest you to check out for any add-on that you must have installed in Firefox 14 and I suggest you to remove it. The add-on which must be interrupting with the installation of Firefox 15 must have not been upgraded by the developers to work with Firefox 15.

You can get into the safe mode of the operating system that you are using and then start Firefox 14 or 15. In safe mode, every add-on and extension will be disabled. The Firefox 14 will start as it has no add-on in it. Then you can get into the add-on manager, that is, ctrl + shift + a.

Here you can disable or uninstall the add-on to get the Firefox running without the error which is being caused by jar:file:///C:/Program Files (x86)/Mozilla Firefox/omni.ja!/ I think this will solve your problem for sure.