Why my zap was looping endlessly
I swear nothing makes me more anxious than opening Zapier in the morning and seeing a warning banner that says I used up most of my monthly tasks overnight. No new data should have gone in. Nothing should have fired. But when I actually click in, I can see the same thing happening hundreds of times in a row. For me it was a webhook from a form tool that always double fired whenever someone hit submit, but Zapier didn’t treat it as a duplicate. Instead it just happily ran both and then ran the next step twice and on it went while I was making coffee 😛
The thing that clued me in was checking the Zap history and realizing every single log event had timestamps that were less than one second apart. Some were even the same second. When that happens, it almost always means the hook is firing twice either because of a setting in the source app or because Zapier retried. The small table I drew on a sticky note looked like this:
Trigger Time | Action Count
12.01.04 | 2
12.01.08 | 2
12.01.23 | 2
That’s how I convinced myself it wasn’t the later steps creating the loop, it was the upstream trigger duplicating.
The scary error about missing fields
Another fun surprise was when my Zap started throwing errors but the errors didn’t make any sense. The run history said something like “Field cannot be left blank” but the field it was talking about wasn’t even visible in the setup screen anymore. I literally sat staring at an empty box where a dropdown should have been. What I learned is that Zapier doesn’t always refresh the data structure when the source app changes its API. I had changed a column name inside Airtable and kept wondering why Zapier no longer recognized it. Even after reconnecting the account, the dropdown showed the old field labels which just… disappeared in Airtable.
The fix was random trial and error. First I reselected my base and table. No good. Then I switched steps off and back on, still empty. Finally I deleted the dropdown mapping, hit test, and suddenly it showed my new fields. Pretty annoying that deleting was the only way Zapier forced a refresh. Lesson: if a dropdown goes blank, don’t trust the UI. Blow it up and remap from scratch ¯\_(ツ)_/¯
Authentication tokens time out overnight
This one got me multiple times: I would connect Google Sheets, everything works for a week, then suddenly the Zap stops running with the reddish error “auth expired.” I assumed Zapier would just refresh on its own, because Google uses OAuth, but nope. Sometimes the token really just expired and Zapier can’t auto renew unless you manually reconnect. Clicking reconnect always worked, but it makes me nervous because if I leave something over a long weekend, it means the Zap might not fire.
Something weird happened though — when I checked the console output of my own tests, I was able to see the 401 error coming back directly from Google:
“`
ERROR 401 Unauthorized
Request had invalid authentication credentials
Please reconnect your account
“`
Once I saw that raw log, I finally trusted that it wasn’t a Zapier bug. The fix became part of my checklist: anytime a Zap dies in the middle of the night, reconnect the app before wasting time on the steps.
Using paths and accidentally trapping data
The first time I tried using paths in Zapier I thought it would be easy. You just say “if this then go left, otherwise go right.” But what I didn’t realize was that Zapier treats empty values as false. So if you map a field that might not exist, it basically dumps that path and the data hits a wall. I had it happen with a Slack notification where some form fields were optional. If they were blank, my condition literally killed the whole run. I didn’t know this until I found like twenty test submissions in the task history with a gray arrow and nothing else.
The hack I discovered was to always wrap those conditions in a more explicit rule. Instead of just checking if the field equals something, I also add a line saying the field exists. It feels unnecessary until you lose data because Zapier decides that nothing means false. Kind of ridiculous but at least now I know to pad my conditions with artificial checks so nothing gets trapped.
The open tabs chaos during rebuild
Rebuilding is what I do almost every month at this point. The structure that looked brilliant in January ends up broken by March and I always have too many browser tabs open to fix it. I usually have Airtable open in three different views, two Zapier tabs (one editing, one history), plus my Gmail to send myself fake test emails. Sometimes I’ll even open Make just to see if I can replicate the flow there because maybe Zapier is cursed that day.
I always end up lost in which tab has the latest version. More than once I edited a Zap, refreshed the wrong tab, and thought my changes disappeared. They didn’t, I was just inside the earlier draft. I don’t really have a solution besides writing something dumb in the name field of my test Zaps, like “DON’T TOUCH THIS – new” so I can tell them apart. Not professional but it keeps me half sane.
Filters that broke because of capitalization
Here’s a silly one. I had a Zap filter that was supposed to only pass tasks marked as “done.” Worked perfectly in tests, then failed on real data because the app actually sent “Done” with a capital letter. Zapier is case sensitive so it treated them as completely different words. The effect was every real submission being blocked and me sitting there puzzled why nothing flowed through. Fixing it meant adding the OR operator and listing both Done and done. For peace of mind I actually added like four variations: DONE, Done, done, DoNe… just in case. Overkill? Sure. But no more missed tasks. 🙂
Learning to test with real ugly data
The last lesson I keep relearning is that testing with perfect examples is a trap. Zapier always makes those clean little test rows with properly filled out fields and nice capitalization. But real world submissions are full of extra spaces, missing emails, long strings that break Slack messages, or null values that choke filters. When I test, everything looks great. When users do it, chaos. These days I force myself to submit nonsense test entries: fake emails with no at symbol, phone numbers that are too short, messages with weird punctuation. It feels tedious but at least when my Zap runs into ugly inputs I already know how it will behave. The best part is I stopped waking up to midnight notifications that a flow died just because someone forgot to type a last name.
The stubborn delay step nobody talks about
One of my favorite workarounds that saves me constantly is slipping in a tiny delay step between my trigger and the first action. There are times where the app fires before the data is fully available. For example, Airtable sends the hook instantly when a record is updated, but sometimes the linked field hasn’t written the new value yet. If I act right away, I capture the old state. But if I add a delay of just a few minutes, suddenly everything works. It feels like a hack but really it’s just letting the app finish writing before Zapier grabs the data. I wasted hours before learning that trick. So now most of my flows—whether they need it or not—have a delay step baked into them like training wheels.
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Sometimes I think half my role isn’t automation, it’s babysitting the quirks and moods of all these tools interacting. The software acts more like coworkers than systems, with random behavior swings and silent failures, and I keep patching around them with duct tape delays, double filters, and random reconnect buttons.