Hello,
I have a 2012R2 server with some shares on it that was setup to use "anonymous login" (which shows at the server as the guest user) for authentication. All of a sudden, this week we are getting many access denied errors on Win10 clients. I understand that there are now also some Win7 clients with the issue. The workflow used to be 1) Access \\server in explorer 2) see the shares without entering any creds. None of the clients are on our domain so this is the way we set it up to not have to used credentials.
When the credential dialog pops up, I can put in any username without a password and it displays the shares. If I just click enter without any username or password, it gives me the access denied message. Same behavior at the commandline with "net view" or "net use"
At first, I figured it was the 1607 Win10 update, but now I've found some 1511 clients that are doing it. Worse is that I have at least one Win10 1607 client that works just fine with no creds. Could this be something that changed as part of patch Tuesday? If I can have some help in troubleshooting I'm very willing to provide logs.