Issue  

In Constellation‑based applications when a data view error occurs, the UI displays an additional generic error message even when custom error messages have been explicitly configured. 

Symptoms  

The UI itself is behaving as designed. An error banner is shown at the top of the screen, and all error messages returned by the DX API data view response are rendered without filtering. 

Observed behavior includes:  

• Multiple error messages displayed in the error banner for a single data view failure. 

• Client‑configured custom error messages appear correctly. An additional generic error message is always shown alongside custom errors. 

• All errors originate from the DX API response and are rendered verbatim by the UI. 

• Errors occur during advanced searches or runtime data page failures. 

Error

 One of the errors consistently displayed is: 

 “An internal error occurred while fetching the results using data view. Please contact administrator.” 

 This message is returned by the DX API together with the custom error messages. As a result, the Constellation UI components render both messages simultaneously.  

Steps to reproduce  

1. Configure UI that consumes a data page, for example, a landing page list or a Search and Select component. 

2. Define a custom error message in the response data transform of the data page. 

3. Trigger a scenario where the data page returns an error. Observe that two or more error messages are displayed based on the configuration. 

  Root Cause   

This is a limitation in how the product handles error messages in the Constellation UI feature.  

The issue is caused by a recent change in DX API Data View error handling, which enabled the use of meaningful, client‑configured custom error messages.   

As part of this change, the legacy default generic error message was not removed. Instead, both the default system error message and any configured custom error messages were returned together in the same DX API response.  

  
 Solution  

A permanent fix is set to be delivered in Pega Infinity™ 26.1. 

The fix modifies error handling across all layers so that:  

1. The default generic error message is no longer appended when custom error messages are present.

2. Custom error messaging is displayed cleanly without duplication. 

3. Unwanted Error_Execution_Error messages have been resolved.

4. HTTP error code previously showing as 500 has been resolved.

5. Error banner collapsing when multiple messages are present has been resolved.

References

Understanding a Constellation DX API response 

Data endpoints     

Error handling in a Data Page