Can't connect to SMB share "Windows cannot access"

Question

I use my NAS for backups (truenas), with an SMB share. I reset my PC recently and added it like normal. Worked fine. However, after a day it stopped working and I was unable to connect to it. Now when I try to connect to it I get this:

It works fine on my laptop

^ Before the error box appears (after loading for quite a while)

I tried:

• Redoing the ACL perms
• Adding network location
• Typing IP address in the file path
• Tested: "\192.168.244.3", "\192.168.244.3\MainBackup", "\192.168.244.3\MainBackup\MainBackup"

I was told to post this here

Answer 1

Currently facing this same issue with Windows 10, either I get "Windows cannot access" or "The folder you entered does not appear to be valid" errors. I've tried all the guides without luck.

Answer 2

I had a similar problem with a Synology NAS

It was solved by forcing Windows to use NTLM2 only
I have set it, using a GPO, as I want it, for all servers and DC's.
Also when We add new servers.

Screenshot is from secpol.msc.