This is an error message from Tray indicating there's an issue with the connector's attempts to process your data. The most common reason for this error is attempting to send a payload that is too large.
Here's a quick summary of Tray's data payload limits:
|Data that can pass between any 2 steps in the workflow builder||1 MB||any more will cause issues|
|Data that can be sent using the Trigger Event Reply||1 MB|
|Data that can be consumed by our Webhook Trigger||1 MB||file content can be sent as multi-part http requests, with an overall limit of 10MB|
|Data that can be sent via the Form Trigger||1 MB (10 MB for attached files)|
|Data that can be attached to an inbound email||10 MB|
You can read more about Tray's technical limits here.