Troubleshooting Terminal Services Administrative Resource: Common Issues & FixesTerminal Services Administrative Resource (TSAR) refers to tools and services used by administrators to manage Windows Remote Desktop Services (RDS)/Terminal Services environments — including session management, licensing, resource allocation, and administrative connections. Large deployments can suffer from configuration drift, network issues, licensing problems, and performance bottlenecks. This article covers common issues, diagnostic steps, and practical fixes to restore stability and improve reliability.
1. Understanding the components
Terminal Services environments typically include these components:
- RD Session Host (RDSH) servers that host user sessions.
- RD Connection Broker for load balancing and reconnection to existing sessions.
- RD Web Access for browser-based access.
- RD Gateway for secure remote access across firewalls.
- RD Licensing server to manage CALs (Client Access Licenses).
- Administrative tools and scripts (the “Administrative Resource”) used to monitor, patch, and configure the environment.
2. Common issue: Users cannot connect
Symptoms: Users get “remote desktop can’t connect to the remote computer” or “The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license.”
Diagnostic steps:
- Verify basic network connectivity (ping, tracert) between client and RDSH/RD Gateway.
- Check RD Gateway and firewall rules (ports 3389 for RDP, 443 for RD Gateway).
- Confirm the RD Connection Broker and RD Session Host roles are online in Server Manager.
- Review event logs on RDSH and RD Gateway: look under Applications and Services Logs → Microsoft → Windows → TerminalServices.
- On clients, ensure correct server name and that DNS resolves correctly.
Fixes:
- Re-open or add firewall rules for RDP and RD Gateway.
- If DNS issues, add correct DNS records or use hosts file for testing.
- Restart the RD Connection Broker service and RD Session Host or reboot affected servers.
- If the error references licensing, verify the RD Licensing server is configured and reachable.
3. Licensing problems
Symptoms: Users can connect for a short time then receive messages about license limits, or the licensing server status shows “unavailable” or “not activated.”
Diagnostic steps:
- On the RD Licensing server, open the RD Licensing Manager and check the server activation state and issued CALs.
- Confirm the RD Session Host servers point to the correct Licensing server (Group Policy: Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → Remote Desktop Session Host → Licensing).
- Check system time and time zone on all RDS components; large clock skew can prevent license validation.
- Review Event Viewer for licensing-related events (IDs typically in TerminalServices-Licensing log).
Fixes:
- Activate the RD Licensing server if not activated (use the Licensing Manager or Microsoft Clearinghouse).
- Reinstall or reconfigure the licensing role if corrupted.
- Apply the correct licensing mode (Per User vs Per Device) in RD Session Host Configuration or Group Policy to match purchased CALs.
- Ensure license server discovery is enabled via GPO or registry and that network ports used for licensing are open.
4. Performance and resource exhaustion
Symptoms: Slow logon times, high CPU/memory on RDSH, frequent session drops, or “server is out of resources” errors.
Diagnostic steps:
- Monitor CPU, memory, disk I/O, and network on RDSH using Performance Monitor (perfmon) and Resource Monitor.
- Identify processes consuming excessive resources (Task Manager or Process Explorer).
- Check profile size and user logon scripts causing delays.
- Evaluate number of concurrent sessions vs server capacity.
- Look for antivirus scans or backup jobs running at peak times.
Fixes:
- Scale out: add more RD Session Host servers and adjust load balancing via RD Connection Broker.
- Tune profiles and redirect folders (roaming profiles, folder redirection, and FSLogix for profile containers).
- Optimize Group Policy: reduce synchronous policies and large logon scripts.
- Exclude RDS profile paths from real-time antivirus scans and schedule maintenance windows for backups.
- Increase server resources (CPU, RAM, disk speed) or use SSD for profile storage to reduce I/O bottlenecks.
5. Session disconnection and reconnect issues
Symptoms: Users unexpectedly disconnected or cannot reconnect to existing sessions.
Diagnostic steps:
- Check RD Connection Broker health and connectivity; the broker tracks session ownership.
- Review event logs for disconnect/reconnect events on RDSH and Connection Broker.
- Verify licensing and session limit settings.
- Check idle/timeouts configured in Group Policy or Session Host Configuration.
Fixes:
- Restart RD Connection Broker and ensure SQL or WMI backend (if used) is healthy.
- Adjust session timeout settings to appropriate values for your environment.
- Configure reconnection settings to allow users to reconnect to existing sessions and verify the RD Connection Broker database isn’t corrupt.
- Keep session state on the same collection or farm by ensuring Connection Broker has correct server list.
6. Printing and device redirection failures
Symptoms: Printers, drives, or smart cards not available in remote sessions.
Diagnostic steps:
- Confirm Remote Desktop Client settings have device redirection enabled.
- On server, verify Group Policy isn’t disabling redirection (Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → Remote Desktop Session Host → Device and Resource Redirection).
- Check spooler service on the RDSH and driver compatibility for redirected printers.
- For universal printing, ensure the required Role Services and drivers are installed.
Fixes:
- Enable necessary redirection policies and install compatible printer drivers (or use Easy Print/Universal Print Driver).
- Restart the Print Spooler service.
- Use third-party solutions or Microsoft’s Easy Print to reduce driver conflicts.
- Ensure USB/Smart card redirection services and listeners are enabled on both client and server.
7. Security and credential delegation issues
Symptoms: Applications prompt repeatedly for credentials, double-hop authentication fails, or Group Policy preferences fail under constrained delegation.
Diagnostic steps:
- Identify if the issue involves Kerberos constrained delegation (double-hop scenarios: client → RDSH → file server).
- Check if “Allow delegating saved credentials” and “Allow delegating fresh credentials” policies are configured correctly (Group Policy → Computer Configuration → Administrative Templates → System → Credentials Delegation).
- Review SPNs (Service Principal Names) for RDSH and related services using setspn.exe.
- Check event logs for authentication errors (Kerberos, Security).
Fixes:
- Configure appropriate delegation settings and add SPNs for the RDSH and service accounts.
- Use Kerberos where possible; if not supported, use NTLM fallback carefully.
- Ensure service accounts are configured with correct permissions and not using local accounts that cannot be delegated.
8. RD Web Access or RD Gateway web portal issues
Symptoms: RD Web Access shows blank pages, slow load, or users cannot launch remote apps.
Diagnostic steps:
- Test IIS website health: check application pools, bindings, and SSL certificates.
- Review RD Web Access and RD Gateway logs in Event Viewer and IIS logs.
- Validate certificate trust chains on client and server.
- Confirm the RD Gateway’s CAP/NAP policies and authentication methods (RD Gateway Manager).
Fixes:
- Recycle or recreate application pools; ensure the application pool identity has proper permissions.
- Renew or rebind SSL certificates; ensure clients trust the issuing CA.
- Fix any broken virtual directory settings and ensure the RD Web Access web.config contains correct connection strings.
- Update RD Web Access and Gateway role services and apply Windows Server updates that patch known issues.
9. Admin tools and automation failing
Symptoms: Scripts or administrative tools that manage sessions or perform bulk operations fail or return inconsistent results.
Diagnostic steps:
- Check compatibility of PowerShell modules and RSAT tools with server OS versions.
- Run scripts with elevated privileges and check execution policy.
- Log detailed errors and replicate commands interactively to isolate failures.
Fixes:
- Update PowerShell modules and use the latest Remote Desktop Services management cmdlets.
- Sign scripts or adjust ExecutionPolicy temporarily for troubleshooting.
- Use try/catch and verbose logging in administrative scripts to capture failures and retries.
10. Proactive maintenance and best practices
- Keep RD roles on supported Windows Server versions and apply security/feature updates promptly.
- Use monitoring (PerfMon, SCOM, third‑party) to alert on CPU, memory, disk, and session counts.
- Implement high availability for Connection Broker and RD Licensing (use SQL-backed broker for larger farms).
- Document configuration (GPOs, firewall rules, certificates) and use version control for automation scripts.
- Regularly test backups, licensing renewals, and disaster recovery procedures.
Conclusion
Resolving Terminal Services Administrative Resource issues requires structured diagnosis: check connectivity, licensing, broker health, resource usage, and policies. Apply targeted fixes—reconfiguring licensing, tuning performance, adjusting policies, and maintaining role services—to restore reliable operation. For persistent or complex failures, collect logs from RD Connection Broker, RD Session Hosts, Licensing server, RD Gateway, and IIS; these artifacts make vendor support or escalation far more effective.
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