Forum Discussion
Windows server 2025 SQL patching cluster problem.
Dear Team,
I have a problem when I am patching upgrade windows server 2025 with KB5091157. After patching is the clustering is not able to join back; it shows the error with credentials. The log error is "Cannot connect sqlxxxxxxx." you do not have administrative privileges on the cluster. Contact your network administrator to request access.
Note: The server is not in a different VLAN network.
1 Reply
Hi, start by confirming whether the node actually rejoined the Windows Failover Cluster before troubleshooting SQL. From a healthy node, check cluster node state, run cluster validation for networking/system configuration, and generate a cluster log around the failure time. Verify DNS, time synchronization, domain-controller reachability, the Cluster Service account context, and the affected administrator's cluster access. Endpoint security or a post-update policy can also block remote cluster management even in the same VLAN. If removing KB5091157 from one test node restores normal behavior, document that evidence and open Microsoft support cases for both Windows clustering and SQL before patching the remaining nodes.
