Accented characters (Ä, Ö, å) in attachment filenames converting to “?” + Unable to trace end‑user session from Dev Studio (Infinity 25.1.1 Constellation)

General
1

We are facing two issues in our Pega Infinity 25.1.1 (Constellation) application and would appreciate guidance from the community.

1. Accented characters in attachment filenames are being converted to “?”

When an end user uploads a file whose filename contains the accented characters Ä, Ö, or å, Pega automatically replaces those characters with question marks in the end‑user portal.

Example:

  • Original filename: Dokument_ÄÖå_Testfil.pdf

  • After upload (end‑user portal): Dokument_???_Testfil.pdf

Important observations:

  • This issue is consistently reproducible in the end‑user portal.

  • The same file uploaded using a Dev Studio operator ID retains the correct filename — no characters are replaced.

  • Because of this difference, we want to understand whether this behavior is:

    • Expected OOTB behavior in Constellation,

    • A platform‑level filename sanitization rule,

    • A browser/client‑side restriction,

    • Or something specific to our application configuration.

We are specifically trying to understand how Constellation handles Unicode / extended Latin characters in filenames and why the behavior differs between end‑user and Dev Studio sessions.

2. Unable to trace end‑user session from Dev Studio (Remote Tracer issue)

To investigate the filename conversion issue, we attempted to use Remote Tracer from Dev Studio.
However, we are not able to trace the end‑user operator session (our test user ID).

Details:

  • The end‑user session does not appear in the list of available sessions when starting Remote Tracer.

  • Since the filename issue only occurs in the end‑user portal, remote tracing is required to identify where the filename transformation is happening.

  • We would like to confirm:

    • Whether Remote Tracer is supported for Constellation UI sessions in Infinity 25.1.1,

    • Whether any additional configuration is required to enable tracing of end‑user sessions,

    • Or if Pega recommends an alternative debugging approach for Constellation.

Summary

We are looking for guidance on:

  1. Why accented characters Ä, Ö, å in attachment filenames are being converted to ? only in the end‑user portal.

  2. Why Dev Studio can not trace the end‑user operator session in Infinity 25.1.1 Constellation, and whether Remote Tracer is supported for this UI.

Any insights, documentation references, or suggestions would be greatly appreciated.
Thank you in advance for your support.

2

This issue is specifically a platform-level filename encoding mismatch:

  • The file upload handler in Pega 25.1 is using ISO-8859-1 character encoding by default instead of UTF-8

  • This was introduced with the migration to Jakarta Servlet APIs in Pega 25.x, which enforces strict UTF-8 validation during multipart request parsing

  • When browsers send attachment files with UTF-8 encoding (which includes accented/special characters), the system cannot properly interpret them

Not Related To

  • This is not an expected behavior in Constellation UI

  • This is not caused by browser/client-side restrictions

  • This is not specific to your application configuration

Solution

Pega has created a hotfix to address this specific issue:

  • HFIX-D334 for Pega 25.1.1 corrects the file upload process to properly use UTF-8 character encoding

  • After applying this hotfix, filenames with accented characters and Unicode characters will display and function properly

Temporary Workarounds

Until the hotfix can be applied:

  1. Rename files before upload to remove accented characters

  2. Add -Dfile.encoding=UTF-8 to the JVM startup parameters and restart the server

Also check out Enabling Unicode character support for object names and the References in article Working with CSV Files in Pega Platform, for example Supported locales in Constellation

2 Likes
3

@MarijeSchillern Very informative article and apt reply :+1:

https://forums.pega.com/invites/3YD9bY5XoM