CSS/HTML Parsing Exceptions when rendering Outlook .msg files in GropDocs.Viewer for .NET

GroupDocs.Viewer Product Family
1

Hi Support Team,
We are encountering two fatal parsing errors when attempting to render certain Outlook .msg files. The issues appear to stem from the viewer’s HTML/CSS engine strictly parsing the improperly formatted HTML typically generated by email clients.
Here are the details of the two specific errors we are seeing:

  1. The “CommaToken” Parsing Issue
    The parser fails when reading a font-family declaration that contains encoded HTML quotes ("). It throws the following error:
    “Internal error - Preserved token with type ‘CommaToken’ and content ‘,’ is not permitted in declaration block. Overall content of input Simple block is ‘font-family: “Segoe UI Web (West European)”, “Segoe UI”, -apple-system, BlinkMacSystemFont, Roboto, “Helvetica Neue”, sans-serif; font-size: 16px; color: rgb(0, 0, 0);’.”
  2. The “Invalid Class Name” Issue
    The parser rejects HTML class attributes that start with a number (e.g., class="2"). While this violates standard W3C specifications, it is very common in raw email HTML. The application crashes with this error:
    “Class name ‘2’, which occured on ‘0’ 0-based position in the input class names ‘2’, is invalid: Class name cannot start from the ‘2’ character Parameter name: classNames”

I have attached the screenshots of the errors for your reference. Looking forward to your advice.
Screenshot 2569-07-30 at 18.49.07.png (86.1 KB)

Screenshot 2569-07-30 at 18.49.27.png (61.0 KB)

Best regards,
Prapas

2

@prapapra

Hi Prapas,

We will fix both these issues by tuning and adjusting our HTML/CSS parser, but we need a sample file, which we can use for reproducing the reported issues.

Thanks and waiting for the file.

With best regards,
Denis Gvardionov