# 503
source: https://developer.mastercard.com/open-finance-us/documentation/errors/error-codes/503/index.md

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

|             Title             |                                                                                                                                                   Details                                                                                                                                                    |
|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Aggregation Status Code**   | 503                                                                                                                                                                                                                                                                                                          |
| **Remediation Category**      | Retry Later                                                                                                                                                                                                                                                                                                  |
| **HTTP Status**               | 500                                                                                                                                                                                                                                                                                                          |
| **Error Type**                | Account Error                                                                                                                                                                                                                                                                                                |
| **Data Connect Alert**        | Internal Server Error. (503)                                                                                                                                                                                                                                                                                 |
| **Error Message**             | During getting URL, A timeout occurred while waiting for a response from the port specified.                                                                                                                                                                                                                 |
| **Common Causes**             | This error can occur due to any of the following reasons: * When an end user is not responsive either during an add account event or Multi-factor authentication (MFA). * Data Connect session expired, which resulted in token becoming invalid. * The end user chose to cancel the Data Connect session. ​ |
| **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)