[BUG] Converting circular structure to JSON --> starting at object with constructor 'Object' --- property 'default' closes the circle

Hi community,

This workflow has been running for a few months now with barely any issues.
However, starting about 30 minutes ago, I started getting the following bug:

Nothing shows up in the workflow interface, not even on the webhook node, so I think it’s coming from the source code.

Would appreciate any help :slight_smile:


This error would suggest somewhere in your workflow n8n is trying to stringify a circular structure as described for example here:

In order to find and isolate the issue, I’d go through the changes you might have made prior to the update, revert them and see if any of these might have caused the problem.

As a next step, you might want to narrow down the problem by looking at individual parts of your workflow. For example, remove everything after the first 10 nodes and see if that works. Then add back in the next 10 nodes and re-try. Repeat this until you find which part is causing the problem.

Hi MutedJam,

Thanks for your prompt reply!

Sadly, I can’t debug anything in n8n because no data is showing up in the nodes. And we haven’t updated this workflow in weeks.

Well, the workflow isn’t the only thing that can change. Did you upgrade your n8n version or did the input data change maybe?

Last update was 0.151.0, which was released 3 weeks ago - and no change in input data :confused:

I’ll try updating it first.