Hi Ravi Chandran,
Thanks for contacting syncfusion support.
Kindly make sure the assemblies MSVCP100.dll and MSVCR100.dll are available in the C:\Windows\SysWOW64 location.
Also make sure the Syncfusion.HtmlConverter.Base.dll assembly is not blocked. If it is blocked, you can unblock the assembly from its property window. Please find the attached screen shot for your reference.
Can you please let us know your WebKit HTML convertor version?
Please try the above steps and let us know the results.