# 504
source: https://developer.mastercard.com/open-finance-us/documentation/errors/error-codes/504/index.md

This error occurs when the end user session has either expired or timed out.

|             Title             |                                              Details                                              |
|-------------------------------|---------------------------------------------------------------------------------------------------|
| **Aggregation Status Code**   | 504                                                                                               |
| **Remediation Category**      | Retry Later                                                                                       |
| **HTTP Status**               | 500                                                                                               |
| **Error Type**                | Account Error                                                                                     |
| **Data Connect Alert**        | We ran into a connection issue, try again later or select another institution. (504)              |
| **Error Message**             | Error Connecting Account - Please Try Submitting Again.                                           |
| **Common Causes**             | This error occurs when the gateway times out.​                                                    |
| **Troubleshooting Steps**     | Restarting a new Data Connect session is recommended. ​                                           |
| **Data Connect Fix Eligible** | No.                                                                                               |
| **Retriable by End User**     | No.                                                                                               |
| **Access to Latest Data**     | You will be unable to access the latest data for this user's account until the issue is resolved. |

[Full Error List](https://developer.mastercard.com/open-finance-us/documentation/errors/error-list/index.md) \| [Account Errors](https://developer.mastercard.com/open-finance-us/documentation/errors/account-errors/index.md)