File upload error on multiple websites

[leoliva]

Ever since downloading Windows 10, I have been unable to upload PDFs to a couple of different websites, namely dropbox and an online file converter (smallpdf.com). It either says there was an error or says its uploading but never does after a long time (hours). I have also been having similar issues uploading .PNG files to facebook messenger as well, I assume the issue is related to that of the PDFs. I've already tried resetting my web browser (Firefox), re-downloading the files, re-starting my computer, and uploading files from different file locations.The issue persists when on different wifi networks.

Any advice?

 

[Trouble]

It might be a third party security suite.
If you have anything like that installed you might want to consider uninstalling it, leaving only the native Defender product and the Windows Firewall for the time being until you get it sorted out.