Hi everyone 👋
I’m running a ManyChat → n8n → ManyChat automation that used to work perfectly fine until recently.
Now, every time I try to send a message through the ManyChat API using n8n’s HTTP Request node, I get this error:
400 - {"status":"error","message":"validation error","details":{"messages":[{"message":"Subscriber does not exist"}]}}
At first, I thought it was a permission or token issue — but after debugging, I noticed something strange:
👉 The last digit of the subscriber_id sent from n8n is different from the actual subscriber_id shown inside ManyChat.
Example:
-
Actual ID in ManyChat:
25021534494149752 -
ID sent in the API request:
25021534494149750
That one-digit difference causes the ManyChat API to reject the request with “Subscriber does not exist”, even though the user is active and subscribed. How to fix
