Hi Jay,
Thank you for your interest in Syncfusion Products.
For executing web application using Essential DocIO, the following assemblies need to be referenced. Since your application uses DocIO feature all these assemblies need to be referenced in your web application.
• Syncfusion.Core.dll
• Syncfusion.Compression.dll
• Syncfusion.DocIO.Base.dll
For more information about the dll requirements, please refer the below link
http://help.syncfusion.com/ug_93/Reporting/DocIO/ASP.NET/default.htm?turl=Documents%2F231dlls.htmTry referring these assemblies in your application and let us know whether the issue is resolved. If the issue still exists, please provide us with your sample application for further investigating on this issue.
Please let us know if you have any questions.
Regards,
Poornima