Trello Card Creation with File Attachments Results in "Access Denied" Error in Zapier

[Hiren Patel]

In a Zapier workflow, a Trello card is being created with some files attached as attachments. Previously, this was working fine, but for the past few days, I’ve been encountering an "Access denied" error when creating the card. After troubleshooting and checking all possibilities, I discovered that the issue arises when attaching files. If I remove the attachments, the card is created successfully. However, when more than two files are attached, the card creation fails and gives the same error.

I’m unsure why this is happening. It could be due to recent changes or updates made by Trello or some other reason.

If anyone knows why this issue is occurring, please share your insights.

[Luciana Munhoz]

Hi Hiren! Welcome to the Trello community! 

I understood that the error happens when a card is created during the Zapier workflow.
Zapier is a 3rd party Power-up and isn't developed or managed by us.

I'd recommend reaching out to the team who developed the Power-up directly, as they should be able to help you check the Zapier workflow and why is currently generating an error. You can contact them by emailing them at contact@zapier.com

Feel free to let us know if you have any other questions or concerns.

[Hiren Patel]

Hello Luciana, could you please let me know if there are any limitations on file attachments?

[Luciana Munhoz]

Hi Hiren, yes. There are some limits to keep the performance. 

36000 attachments per API request
1000 attachments per card
36000 attachments per board

You can check Trello hard limits here: https://trello.com/1/resource/limits 

Additionally, there is a 10 MB file upload limit per attachment for Free plan.
Paid members have a 250 MB file upload limit per attachment.

Hope that helps!