Troubleshootinglink

401 Unauthorizedlink

Symptoms: The MCP server responds with a 401 status code. Your assistant may show an error like "authentication failed" or "unauthorized."

Causes:

• The X-Radzen-Key header is missing or contains the wrong value
• Your trial key has expired (trials last 15 days)
• You have a typo in the key — extra spaces or missing characters

How to fix it:

1. Open your MCP configuration file and verify the key matches exactly what you received. Watch out for trailing spaces or line breaks that some editors add when pasting.
2. If you're on a trial, check when you registered. Trial keys expire after 15 days regardless of how many requests you've used.
3. If the key looks correct, try generating a new trial key at radzen.com/blazor-mcp or use your paid license key.

429 Too Many Requestslink

Symptoms: The MCP server responds with a 429 status code after some requests succeed.

Causes:

• You've used all 50 requests included in the free trial
• You're sending too many requests in a short time window

How to fix it:

1. If you're on a trial, this means you've hit the 50-request limit. Upgrade to a paid plan for unlimited usage.
2. If you're on a paid plan and still seeing 429 errors, wait a moment and try again. This is a rate limiter protecting the server from excessive load — normal usage shouldn't trigger it.

Connection Refused or Timeoutlink

Symptoms: Your editor shows "connection refused," "connection timed out," or "server unreachable." The MCP server never responds.

Causes:

• Incorrect server URL in your configuration
• A firewall, proxy, or VPN is blocking outbound HTTPS connections
• Rare: the MCP server is temporarily down

How to fix it:

1. Verify the URL is exactly https://app.radzen.com/mcp. A missing s in https, a typo in the domain, or an extra path segment will all fail.
2. If you're behind a corporate firewall or proxy, make sure app.radzen.com is allowed. The server uses standard HTTPS (port 443).
3. Try opening https://app.radzen.com/mcp in your browser. If you get a response (even an error), your network can reach the server. If the browser also times out, the issue is network-level.

Assistant Doesn't Use MCP Toolslink

Symptoms: Your assistant responds to Radzen Blazor questions but uses its built-in knowledge instead of MCP. The code may be outdated, use wrong property names, or not match the Radzen Blazor API.

Causes:

• The MCP server isn't configured correctly or isn't running
• You haven't restarted the assistant after adding the configuration
• The config file is in the wrong location

How to fix it:

1. Check that your configuration file is in the right place. Each editor has a specific location — see the setup guide for your editor.
2. Restart your AI assistant or reload the editor window. Most editors only read MCP configuration at startup.
3. Verify the server is connected using the editor's MCP status panel (Cursor: Settings > MCP, VS Code: the start button in mcp.json, Claude Code: claude mcp list).

Assistant Generates Generic Blazor Code Instead of Radzen Componentslink

Symptoms: The MCP connection appears to work, but the assistant produces standard Blazor code (like <table> or <EditForm>) instead of Radzen components (like <RadzenDataGrid> or <RadzenTemplateForm>).

Causes:

• Your prompt doesn't mention Radzen, so the assistant doesn't think to use MCP tools
• The assistant is in a mode that doesn't support tool use (e.g., Cursor's "Ask" mode or VS Code's "Edit" mode)

How to fix it:

1. Include "Radzen" in your prompt. Instead of "create a data grid," say "create a Radzen DataGrid." This signals the assistant to check the MCP server.
2. Make sure your assistant is in a mode that supports MCP tool calls. In Cursor, use Agent mode. In VS Code, use the Agent chat mode.

MCP Tools Listed but Produce Errorslink

Symptoms: The editor shows the Radzen Blazor MCP tools as available, but calling them returns errors or empty results.

Causes:

• Your key is valid but has reached its request limit
• The server experienced a transient error

How to fix it:

1. Check your key status — if you're on a trial, you may have used all 50 requests. A 429 or 401 error in the tool response confirms this.
2. Try again after a few seconds. Transient server errors are rare but possible.
3. If the problem persists, your key may have been revoked or expired. Generate a new one at radzen.com/blazor-mcp.

Still Stuck?link

If none of the above resolves your issue, reach out to us:

• Email: info@radzen.com
• Forum: Radzen Community Forum

Include your editor name, the error message you're seeing, and which step of the setup you completed. This helps us diagnose the problem faster.