ERR_VALIDATION_FAILED on Make.com: Webhook Validation Failed Error. Root cause: Incoming JSON payload structure mismatch against the configured data structure Step 1: Re-determine Data Structure. Right-click the Webhook module in Make, select "Determine Data Structure", and fire a live payload from your source app. Step 2: Decouple Validation. If the upstream payload is dynamic and inconsistent, delete the strict "Data Structure" assignment inside the Webhook configuration. Step 3: Use JSON Parser. Accept the incoming payload as a raw string text block, then pipe it into a JSON -> Parse JSON module to extract variables dynamically without throwing validation blocks.