Normally webserver logs are a gigantic pile of long lines that would choke a browser (if you could even get to the log file in its privileged folder on the server). Does your host offer FTP access to the logs? Then you could download the relevant date and examine it in a text editor like Notepad++. But I'm not sure the problem would be apparent there.

Does the link require a username and/or password to be entered in a pop-up dialog ("basic authentication")? Recent versions of Firefox will suppress that dialog if the link is opened in a frame, so the access will be denied.

A 403 error may be caused by some kind of security on the directory where the file is located, such as the server only serving files to requests with a particular user agent or referer header, or some other detail of the request. You could compare the request headers from a working browser with those from the nonworking browser. Although, sometimes the blockage/modification is caused by privacy settings in the user's security software, so you can't always debug this from inside the browser...

I'm not sure I'm clarifying anything here!

Thank you for the information. I will look deeper into what you told me. I needed to know where to even start to troubleshoot this problem and now I do.

Another quick question though. I posted the link from a mobile device using Firefox. Would posting a link from a mobile device cause the link to operate any differently for someone accessing it form a laptop, tablet, or desktop?

F0xu5er said

I posted the link from a mobile device using Firefox. Would posting a link from a mobile device cause the link to operate any differently for someone accessing it form a laptop, tablet, or desktop?

A link is a link. Can you see anything broken in the link? If not, I think you can set that aside. Not to mention that it's okay for everyone else.

No nothing is broken in the link and it works for anyone else. Must that users device/network/settings like you siad.

Thanks so much for the great info and bearing with me!