Hi Zunino,
navigate to App → system texts.
Here is the corresponding documentation.
Or go to batchtranslate and select the system texts, here you can search and replace.
Hi Zunino,
If you want full control and create the validation microflow yourself you can have any text you want for the validation message. Just choose the validation feedback activity in your microflow: https://docs.mendix.com/refguide/validation-feedback/