To resolve this error first you have to install IIS feature which helps in execution of SSINC-shtm handler.
- Login to Windows VPS server.
- Navigate to Control Panel >> Programs >> Programs and Features >> Turn Windows features on or off.
- Now open IIS (Internet Information Services) >> World Wide Web Services >> Application Development Features.
- Here check all the IIS features like: .NET Extensibility, ASP, ASP.NET, ISAPI Extensions, ISAPI Filters, Server-Side Includes.
- After that under go to Handler Mappings and check for SSINC-shtm your path should be *.shtm and for SSINC-shtml your path should be *.shtml enabled for ServerSideIncludeModule Handler.
- Then in IIS under Handler Mappings, make sure you have SSINC-shtm for path *.shtm, and SSINC-shtml for path *.shtml enabled for the ServerSideIncludeModule Handler.