Hello Heiko,

On this article, you will find the possible ways to change the Spreadsheet's messages.

Please note that we do not have the needed linguistic knowledge to provide translations for all languages. Therefore some of the translations for the Spreadsheet are incomplete. About that, we highly rely on Kendo users to help us on that matter by making contributions with the translations they find are missing. If you are interested in making such contribution, you can follow the steps from this article. Such actions are always appreciated from us and the rest of the community that will benefit from them.

Having said that said, I am declining the current bug report.

Let me know if you have any further questions.

Regards,
Martin
Progress Telerik