Also affects Wyse Thin Os 5070 - but NOT older T series thin clients or original branded Wyse Clients
Before anyone asks - Yes I have a case open with Microsoft, and Dell. Both are pointing the finger at each other and we're going nowhere.
After My posts on patch Tuesday where we determined that KB4503267 was killing Wyse 3040 thin clients (And only wyse 3040 thin clients) we've now determined that KB4503294 is causing this also.
Configuration example:
A single Remote Desktop Connection is configured. The hostname is pointing to internal hostname of server e.g. remote1, and the use TS gateway setting is checked, with the TS gateway pointed to gateway.contoso.com
Symptom: When a user attempts to login the login window on the thin client disappears for a moment and then re-appears
Event log does not show anything useful or conclusive either on the thin client or Windows Security log. All windows security log says is "error during logon". I'll add a complete extract as soon as the box comes back up.
I'm at a loss (And so is everyone else apparently) as to why only the dell 3040's are affected. Even the earlier Wyse T series thin clients are fine and Microsoft can't give me any answers nor can Dell
On Server 2012 we found that Preview updates KB4503295, KB4503277, caused this.
Edit: I previously typed that KB503886, KB4503865 affected this - That information is incorrect and these were not installed on the servers impacted this morning
We also found that non preview updates KB4503263 AND KB4503276 when combined caused this issue.
I was also able to confirm that this affects firmware version 8.6_024 & 8.6_013
An example of the Event log from a failed user logon (with some redactions)
An account failed to log on. Subject: Security ID: NULL SID Account Name: - Account Domain: - Logon ID: 0x0 Logon Type: 3 Account For Which Logon Failed: Security ID: NULL SID Account Name: USERNAME Account Domain: CONTOSO.local Failure Information: Failure Reason: An Error occured during Logon. Status: 0x80090308 Sub Status: 0x0 Process Information: Caller Process ID: 0x0 Caller Process Name: - Network Information: Workstation Name: GATEWAY.CONTOSO.COM Source Network Address: 12.234.234.234 Source Port: 54188 Detailed Authentication Information: Logon Process: NtLmSsp Authentication Package: NTLM Transited Services: - Package Name (NTLM only): - Key Length: 0