Skip to main content

AI Chat Feature Blocked by Proxy or Network Interference with HTTP2 SSE Connections

Angelo Bresci
Updated

Area: Deployment Issues

Sub-Area: Corporate Proxy / Network Configuration Blocking AI Chat (Ask DataHub)

Issue

Users accessing the AI chat feature (Ask DataHub) in a DataHub Cloud instance may encounter intermittent or consistent failures where every question submitted results in an "Oops! An unexpected error occurred" message. The error pattern often presents as: the first message after navigating to the chat page succeeds, but subsequent messages fail — requiring the user to navigate away and return to get one more successful response before the cycle repeats. This behavior is caused by the underlying HTTP2 Server-Sent Events (SSE) connection being closed immediately by a corporate proxy, network security appliance, or traffic inspection tool that intercepts and mishandles long-lived SSE streams.

Error Messages

  • Oops! An unexpected error occurred

You Might Be Asking

  • Why does the AI chat work on my first question but fail on every subsequent one?
  • Why does navigating away from the Ask DataHub page and returning temporarily "fix" the error?
  • Could a VPN client, SSL inspection tool, or corporate proxy be causing Ask DataHub to fail?
  • How do I confirm that my network is intercepting SSE connections to DataHub Cloud?

Solution

  1. Confirm the symptom pattern. Verify that the failure matches the proxy-interference pattern:
    • The first AI chat message after page load succeeds.
    • Subsequent messages fail immediately with a generic error.
    • Navigating away from the chat page and returning resets the cycle (one success, then failures).
    • The issue persists even when a client-side VPN or security agent appears to be disabled, because traffic may still route through a corporate network gateway.
  2. Capture a browser network log to confirm HTTP2 SSE connection termination.
    1. Open a new Chrome or Edge browser window and close all other tabs.
    2. Navigate to chrome://net-export/ in the address bar.
    3. Click Start Logging to Disk and choose a save location.
    4. Reproduce the issue: navigate to the AI chat page, ask a question that succeeds, then ask a second question that fails.
    5. Return to chrome://net-export/ and click Stop Logging.
    6. Review the resulting JSON log file for HTTP2 stream reset events or immediate SSE connection closures directed at your DataHub Cloud endpoint (https://<your-instance>.acryl.io).

    Alternatively, use Chrome DevTools to collect a HAR file:

    1. Open DevTools (F12 or Cmd+Option+I on Mac).
    2. Go to the Network tab and check Preserve log.
    3. Reproduce the error.
    4. Click the download/export icon in the Network tab toolbar to save the HAR file.

    In the HAR or net-export output, look for SSE requests to the AI chat endpoint that are terminated with an HTTP2 protocol error or receive no data frames after the initial connection.

  3. Identify the intercepting network component. Common culprits include:
    • SSL/TLS inspection proxies that do not support HTTP2 SSE pass-through
    • Zero-trust network access (ZTNA) or Secure Web Gateway (SWG) agents
    • Corporate firewall rules that terminate idle or long-lived HTTP2 streams
    • Transparent proxies that buffer streaming responses and drop the connection before the SSE stream completes
  4. Update proxy or network configuration to allow HTTP2 SSE connections. Work with your network security or IT team to apply one or more of the following changes for your DataHub Cloud hostname (https://<your-instance>.acryl.io):
    • Bypass SSL inspection / TLS decryption for the DataHub Cloud domain.
    • Allowlist or exempt the DataHub Cloud domain from proxy interception rules so SSE connections are passed through without buffering.
    • If using a Secure Web Gateway, configure a policy exception that permits long-lived HTTP2 streaming connections to the DataHub Cloud endpoint.
    • Increase or disable connection idle-timeout settings for the DataHub Cloud domain to prevent premature stream termination.

    Example proxy bypass rule (syntax will vary by vendor):

    # Example: add DataHub Cloud to proxy bypass list
# Replace <your-instance> with your actual DataHub Cloud subdomain
NO_PROXY=<your-instance>.acryl.io

# Or in PAC file format:
function FindProxyForURL(url, host) {
    if (shExpMatch(host, "*.acryl.io")) {
        return "DIRECT";
    }
    return "PROXY proxy.example.com:8080";
}
  5. Validate the fix. After the network team has applied the configuration change:
    • Navigate to the Ask DataHub chat page in your production instance.
    • Submit multiple consecutive questions without navigating away.
    • Confirm that all responses stream successfully without errors.

Additional Notes

Ask DataHub uses HTTP2 Server-Sent Events (SSE) to stream AI-generated responses incrementally to the browser. SSE connections are long-lived and may be misidentified by proxy or security appliances as stalled or idle connections, causing them to be prematurely terminated. This is a known compatibility challenge with SSE-based features and network inspection tools — see the broader community discussion at https://github.com/danny-avila/LibreChat/discussions/12038 for additional context. The feature flag for Ask DataHub is managed centrally by DataHub Cloud; if the feature is not visible in the UI at all (rather than returning errors), contact DataHub Support to verify feature enablement for your instance. This issue has been confirmed resolved by updating proxy bypass or SSL inspection settings — no changes to the DataHub Cloud configuration are required on the platform side.

Related Documentation

Tags: ask-datahub, ai-chat, http2, server-sent-events, sse, proxy, corporate-network, ssl-inspection, streaming, network-configuration