I’ve been having this problem for months. I’ve been trying between iPhone, iPad, and Apple TV, iOS 10 and 11, and three different macs on Sierra and now high Sierra. It worked before upgrading the macs to Sierra. Ive tried after updating to 10.13.1. I’ve purchased several versions of Infuse as well.
At least one user is selected under ‘Windows File Sharing’ (as shown under ‘Advanced Options’ in the link above).
Selected username and password are being entered in Infuse.
Note: iCloud username/password cannot be used. If you’re using an iCloud ID to log in to your Mac, you will need to set up a new ‘Sharing Only’ user as described here: https://support.apple.com/kb/PH18695
After updating my server to High Sierra, I had no chance to get connected in SMB with InFuse.
But I noticed after dozen of tests that setting the “Workgroup” (in the InFuse share) helped me to get SMB working.
It’s not 100% working for each attempt, but by trying multiple times, it most surely ends up working while without the workgroup set, it will —always— fail.