This error means that there may be some invalid data on the application.
Please check the vehicle registration as this could be a potential cause of the issue.
You may also need to check for any comma's or invalid characters in email addresses in the notify process.
The details for the error are at the bottom if you scroll down to it - it should provide more details such as Validation Message "Value Contains invalid characters"
If you cannot fix this yourself, please raise a new case online and reference the title of this article.