Custom value for field error messages

[jsimomaa]

Could it be possible to provide a custom error message to serve as fields error message? That way it would be possible to provide a localized message for the end user. Now there is a mix of languages (e.g. English and Finnish):

[benedictdudel]

Would like to see custom multilanguage error messages as well.

To solve your current problem, you could translate the message on your own and contribute translations in Finnish.

[tobbexiv]

You can also change the text of the error message for each field individually, so this is possible.
The setting is on tab "Appearance" of the field edit modal. The field is "Required error message".