If you come across this issue, then please raise a new case online and reference the title of this article.
When raising a case please provide the following:
A screenshot of the error within Mosaic.
Form ID in Mosaic Portal and workstep ID in Mosaic.
Status of the form within Mosaic Portal.
For all non-hosted customers, include framework.log.
Please also confirm if there are any Unicodes identified within the form. You can find this in Mosaic Portal.