A 504 Gateway Time-out error when importing CSV contact data into an event pipeline on Decile Hub usually indicates a server or network issue, possibly due to a large file size or temporary system overload. Try the following steps:

• Reduce the number of contacts in your CSV and attempt a smaller import.
• Check your internet connection and try again after a short wait.
• If the issue persists, contact Decile Hub support for assistance.

You can also review or report your issue directly on the Decile Hub support forum: Decile Hub Support.