I'm running Windows Server 2016. I installed OpenSSL-Light. Still get the error. Strangely the instructions you provided a link to say:
6) Double-clicked the EXE file: Win32OpenSSL_Light-1_0_2L
7) With SEARCH I confirmed that the two dlls were installed. On my system, these files were placed in /Windows/sysWOW64 folder. I did not have to move these files to a different location.
In browser opened my account at Sketchfab.com
9) Clicked the UPLOAD button, upper left corner of window.
10) Navigated to the folder MODEL, double-clicked "model"
11) Photoscan recognizes the presence of the doc.XML, mesh.PLY, and texture.PNG files, and
12 UPLOAD proceeds without error.
#8 and #11 don't make sense as one says "in browser" and the steps after that appear to be using upload function on sketchfab website and #11 says "Photoscan recognizes" I think they mean Sketchfab recognizes as the function in Photo scan is File > Upload > Sketchfab > Specify info including API key -- there's no browser involved!
I still get the SSL error. Do I need to restart Photoscan or the server?