There is a Kirk response somewhere (I can't seem to find it now) dated around the 10th Dec, 2015 saying there would be a fix for the Photoshelter (in PM) uploader issues, namely the "authentication error", which is my current issue with PM 5... I use PM 4.6 right now on my older Windows 7 machine and it's fine, but I need to use PM 5 on a windows 10 machine soon, and wondering if this is something that might actually be fixed in the near future... sorry for sending the same question, but I can't find any answer to this on the forum. Thanks.