C:\Users\myname\photos\pic.jpg

 C:\fakepath\pic.jpg

When attempting to upload a file using [Browse] button in a form on a website, the original filepath, which may be for example: C:\Users\myname\photos\pic.jpg Shows up as: C:\fakepath\pic.jpg This causes the upload to fail. Apparently, this is a feature of HTML 5 "the local path to a file should not be given to any untrusted website. Instead, the browser will replace the actual path with C:\fakepath, and the upload will fail if attempted" The key being here " UNTRUSTED WEBSITE" In my case, yes, it is my router webpage which is using a Cisco self-signed certificate so the https:// is deemed "insecure" - and I need to choose to proceed anyway or add exception (depending on browser) to bypass the SSL warning and pull up the webpage. So yes, I'd say it's being seen as "untrusted" Now the suggested fix is to add the website to the list of "Trusted sites" in IE-speak. How is this accomplished in current Firefox ? I found only a forum post from 2013 that said Tools->Options->Security->Exceptions. Current Firefox "privacy & security" page has 4 [Exceptions] buttons, none of which are an obvious choice in this context!