I am sorry you’re having trouble. A 5xx response is coming from the webserver in front of the actual n8n instance and usually means that n8n itself isn’t responding as it should, often because it us under a very high load or has crashed.
A very common cause for such crashes are out of memory situations as described here. n8n cloud provides limited memory to each instance, and it’s relatively easy to hit this limit.
That said, I couldn’t find an active n8n cloud instance under your forum email, so am not sure if this is what has happened here. If you are still seeing this problem, perhaps you can reach out to [email protected] confirming your instance URL and execution ID so we can take a closer look?