Hi everyone,
A fix for this issue has been scheduled for the upcoming 2025 Q3 release.
In the meantime, we released a knowledge base article that showcases how to work around this issue until the fix is released. For more information, please check Custom Parameter Editors Stopped Working in Progress Telerik Reporting Version 19.1.25.521.
Regards, Petar Progress Telerik
Love the Telerik and Kendo UI products and believe more people should try them? Invite a fellow developer to become a Progress customer and each of you can get a $50 Amazon gift voucher.