Issue Summary

User is receiving an error on the board button they have created.

Error->This action took too long to process, and it may not have finished. If an error occurred, please contact support at Atlassian Support with the reference below and we will look into it promptly.
message: "504 Timeout in request to Trello API",

Steps to Reproduce

This is only reproducible on lists with many cards, or cards with a lot of content and attachments.

Expected Results

The process should not be timing out; alternatively, we should look into whether the timeout limit can be increased

Actual Results

While copying a list, a timeout error is occurring. 

Workaround

Optimize the list operations or split the lists into smaller ones.