You can localize the validation messages in Grid by modifying messages properties of jQuery validator.
Grid Control uses jQuery Validation plugin to show validation messages during CRUD operation.
Those validation messages can be localized by modifying the messages properties of jQuery validator, using extend method of jQuery
Alternatively, jQuery-validation localization files can downloadable from following location.
The following screenshot displays the Grid control with localized validation message.
Figure: Grid with localized validation message
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