Thanks for your inquiry. Please first remove old Aspose.Words completely from your development machine. Then remove the reference to this old Aspose.Words.dll from your project using Visual Studio. Also, delete associated files from your project’s bin folder if present. Then install Aspose.Words (16.3.0) via msi installer. Add reference to this new DLL (~\install-dir\Aspose\Aspose.Words for .NET\bin\net3.5_ClientProfile) in your project using Visual Studio and re-build it. Finally, re-publish your web application and copy the newly published website to your server. Hope, this helps.