Apparently this is tied not to Firefox directly, but to the Adblock Plus addon (3.0.1) from https://adblockplus.org/ . If I disable this plug-in then your page(s) work perfectly fine.  Even if I tell it to not block anything on the domain domain, it will not work if the plugin is enabled.  Has anyone experienced this issue with this ...

Starting with Firefox 56.0.2, ASP Uploader no longer functions properly.  The form shows up, and you can select a file but as soon as you start the upload, the browser logs an error Oxa2 is null.   I have repeated this on 4 seperate computers, and I can verify that it happens on your test page at ...

  Following some more testing, I discovered that you can move the folder and it will continue to use cached files for a while.   After  a restart of IIS, it did discover the new location of the files but how does it arbitrarily choose the path to use? IE - I put the files into webroot\cgi-bin\aspuploader, but as well I had ...

By default you drop the files into: webroot\aspuploader   For programming continuity on our site, I would like to place the files into webroot\cgi-bin\aspuploader.   1, I can drop the  include file where it should go and reference it fine by: <!--#include virtual="/cgi-bin/aspuploader/include_aspuploader.asp" ...

for i = 1 to len(mvcfile.filename)-1  if mid(mvcfile.filename,len(mvcfile.filename)-i,1)=''.'' then   filetype = Right(mvcfile.filename,i)  exit for  end if next This is a simple way, if you run this loop with each uploaded file, it will start with the furthest right character and work backwards until it finds the ''.'' in ...