Summary
On December 3rd, 2025, a “Server error: 504” appeared while I was using GitHub Copilot in Agent Mode on Windows. Although the error looked serious, the final fix was surprisingly simple: I just sent the same request to the agent again, and it worked normally. The issue was nothing more than a temporary timeout.
Error Message like this!
Actual Environment
- Date: December 3, 2025
- OS: Windows
- Editor: Visual Studio Code
- Feature used: Copilot (Agent Mode)
- Situation: Long continuous Agent Mode sessions with multiple commands
- Error displayed (ID anonymized):
Sorry, your request failed. Please try again. Copilot Request id: [redacted] Reason: Server error: 504
Why It Happened
Although 504 is categorized as a server-side timeout, it often occurs because of local conditions:
- Agent Mode running for extended periods
- Multiple heavy requests sent in rapid sequence
- Temporary network congestion
- Internal VS Code processes getting stuck momentarily
This case perfectly matched those conditions.
What Actually Fixed It
The simplest fix worked:
I sent the same instruction to the agent again, and it processed it normally.
No restart, no settings change — the timeout had simply resolved itself.
Other Methods That Usually Help
Even though this time a simple retry was enough, other general fixes include:
- Restarting VS Code
- Re-enabling the Copilot extension
- Avoiding extremely long Agent Mode sessions
- Reconnecting the network
- Updating VS Code and Copilot
Conclusion
This incident shows that a Copilot 504 error is often just a temporary timeout.
In many cases — including this real example — retrying the same request is all it takes. It’s not a critical failure, just a momentary stall in Agent Mode’s processing.
