Flow Designer connection error: cannot load flow

Browser cache corruption or stale ServiceNow session data preventing proper UI initialization and backend communication. (high likelihood)

Service worker conflicts or cached application files interfering with Flow Designer's client-side functionality. (high likelihood)

Corrupt or malformed flow record in the sys_hub_flow table causing backend processing failures when loading flow definitions. (medium likelihood)

Insufficient user permissions to access Flow Designer or specific flow records, resulting in connection authorization failures. (medium likelihood)

Platform plugin issues or missing dependencies related to IntegrationHub or Flow Designer functionality. (low likelihood)

Step 1: Clear browser cache completely and perform a hard refresh (Ctrl+Shift+R or Cmd+Shift+R) to eliminate cached UI components and session data.

Step 2: Log out of ServiceNow completely, close all browser tabs, then log back in with a fresh session to reset service worker connections.

Step 3: Try accessing Flow Designer in an incognito/private browser window to bypass cached data and service worker conflicts.

Step 4: Check user permissions by navigating to User Administration > Users and verify the affected user has the flow_designer role and appropriate ACL access.

Step 5: Examine the sys_hub_flow table for the specific flow record and verify the JSON structure in the flow_definition field is not corrupted or empty.

Step 6: Review Application Logs at System Diagnostics > Logs > Application Logs filtering for 'flow' keywords to identify backend service errors during flow loading.

Step 7: Verify IntegrationHub and Flow Designer plugins are active by checking System Definition > Plugins and ensuring com.glide.hub.integrations is installed and active.

Step 8: If the error persists for specific flows, create a new test flow to determine if the issue is flow-specific or system-wide, then consider restoring the problematic flow from a backup.