Windows 8 and SMB ball in LAN?

Question

Samba

In general, the trouble is as follows:
Trying to mount a disk image (iso, vhdx) from a network share writes "an error occurred while connecting a file
"
the balls are just as unfortunate.
Even trying to do the same from a mapped network drive fails.
On the very first 8.0 everything worked.
After one of the patches, this problem appeared.
In 8.1 the same trouble.
The systems were tested both clean, and with kaspersky, and with komodo, and with completely disabled firewalls and antiviruses.
And in general, with computers it’s far from “you”, I rarely ask questions, mostly I find ready-made answers ... but then I got ambushed ...
They didn’t get banned in Google and Yandex, but am I asking the wrong questions, or I don’t know where to dig ...
I understand that this is limited by some of the policies, but I don’t know how to “return back”.
Does anyone have a wash, where to look / twist?
PS Installing the old version 8.0 in a virtual machine gives the effect "everything works", which confirms the software "improvement" on the part of Microsoft.

Answer 1

In general, the problem turned out to be the SMB configuration of the Synology server.
Enabling "SMB 2 and Large MTU" causes this weird system behavior.
Disabling this option returns the normal functioning of SMB shares.