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Overview

 Error Code 21 (ConnectionTimeout) indicates that the Softdrive client was unable to establish a connection to the remote computer within the allotted timeout period of 5 minutes (300 seconds). 

 This error is similar to Error Code 11 (TCPConnectionFailed), but allows a longer period for the connection to be established before reporting a failure. The issue may occur when the remote PC is unavailable, the Softdrive server process is not responding, or network conditions prevent the connection from completing. 

Applies To

• Softdrive Platform
• Softstream Client
• Cloud PCs

Symptoms

• Error Code 21 – ConnectionTimeout displayed when connecting
• The Softdrive client remains in the connecting state for an extended period
• The connection attempt times out after approximately 5 minutes
• Unable to establish a session with the remote computer

Possible Causes

• The remote PC is powered off or not reachable
• SoftdriveServer.exe is not running or is not responding on the remote PC
• The remote PC is stuck during startup, restart, or Windows updates
• Firewall or network rules are blocking the required TCP traffic
• High network latency, packet loss, or unstable connectivity between the client and remote PC
• Security software, VPNs, or proxy configurations may be interfering with the connection

 This issue is typically related to remote PC availability, TCP reachability, or a connection that cannot be completed within the 5-minute timeout period. 

Resolution

1. Confirm the remote PC is online
   • Verify the Cloud PC is powered on in the Softdrive dashboard
   • If offline, start the machine
   • Wait until the machine has completed its startup process before reconnecting
2. Verify SoftdriveServer.exe is running
   • Check that SoftdriveServer.exe is active on the remote PC
   • If the process is not running or is unresponsive, restart it if you have the appropriate access
   • Retry the connection
3. Allow time for system processes
   • If the PC is restarting or installing updates, wait until the process completes
   • Verify the machine is responsive before initiating another connection
4. Check network connectivity
   • Verify that the local computer has a stable internet connection
   • Confirm that firewalls, proxies, VPNs, or endpoint security software are not blocking Softdrive traffic
   • If possible, test from an alternative network to determine whether the issue is network-specific
5. Use the Troubleshoot option
   • Log in to the Softdrive dashboard
   • Select your computer
   • Click Troubleshoot
   • Once troubleshooting is complete, retry the connection

Validation / Expected Result

• The Cloud PC is reachable and online
• The Softdrive server process is running and responsive
• The connection is established successfully within the allowed timeout period
• The session launches without ConnectionTimeout errors

Troubleshooting Notes

• Error Code 21 is similar to Error Code 11 – TCPConnectionFailed, but uses a longer timeout period of 5 minutes
• The longer timeout allows additional time for the connection to be established, but does not guarantee success if the remote PC remains unavailable
• If SoftdriveServer.exe is not running or responding, connections may time out
• Network restrictions, high latency, or packet loss may prevent the connection from completing
• A connection timeout does not necessarily indicate that the Cloud PC is powered off; additional troubleshooting may be required

Escalation

 If the issue persists, contact Softdrive Support and include the following: 

• Error code: Error Code 21 – ConnectionTimeout
• Date and time of occurrence
• Cloud PC name and organization
• Screenshot of the error message
• Whether the Cloud PC shows as online or offline
• Whether the issue occurs consistently or intermittently
• Whether the issue also occurs when connecting from a different network

 Email: support@softdrive.co