Gets or sets the error text.
A string value that specifies the error text.
If the uploaded file doesn't meet the validation criteria specified via the ValidationSettings property, a specific error text is displayed within the ASPxUploadControl. In this case, the error text may be taken from the FileDoesNotExistErrorText, MaxFileSizeErrorText, NotAllowedContentTypeErrorText or GeneralErrorText properties, depending upon the error's type.
If you perform your custom validation of the uploaded file in the FileUploadComplete event's handler, and the validation fails, you can inform end-users about the error's cause by setting the IsValid property to false, and assigning a specific error explanation text to the ErrorText property.