If you’ve been in software long enough, you know the term. A heisenbug is a bug that disappears or changes behavior when you try to observe it — named after Heisenberg’s uncertainty principle, because the act of looking changes what you see. I hit one in early January, and it almost broke me.

My n8n free trial expired. Time to migrate to a paid account. Should have been straightforward: export workflows, import to new instance, update credentials, done. Except the new instance was running a different version. I’d built on v1.123 but the paid service was on v2.2.6. Some nodes had changed. Some behaviors were different. I ended up rebuilding parts of the system from scratch with the newer node types.

But the migrated workflows wouldn’t work.

Not completely. Parts of it ran. But results were inconsistent. Jobs that should have flowed through didn’t. Data that should have been there wasn’t. The same workflow would succeed when I stepped through it, then fail when I ran it from the orchestrator, then succeed again. No pattern I could find.

I ran in circles for three days. Checked every connection. Reviewed every node configuration. Asked Claude for ideas. Nothing. The system looked correct. It just didn’t behave correctly.

Eventually I did what I should have done sooner: I asked for help. I posted on the n8n Discord and community forums. Within a day, Simon Orlob reached out and walked through it with me.

He saw it too. The configuration looked right. The behavior was wrong. We stepped through the nested workflows together, pinning data between executions to trace the flow.

The fix? Delete the problematic node. Add the exact same node back. Configure it the exact same way.

It worked.

I still don’t know why. Neither did Simon. Something in the node state that wasn’t visible in the configuration. A ghost in the machine that only an exorcism could fix.

The system’s been running flawlessly ever since. Every morning, a fresh email with evaluated job matches — silent validation that the nightmare is over.

The hardest bugs aren’t the ones where you’re wrong. They’re the ones where you’re right and it still doesn’t work. And sometimes the only way through is to ask for help and let someone else confirm you’re not crazy.

Next up: how my relationship with AI tools evolved from copy-paste to something closer to collaboration.