In case of an automatic build/deployment process it might be a request to precompile the web application after building it. Since .NET Framework 2.0 there is a tool called aspnet_compiler.exe. You can use it like that:
aspnet_compiler -v /MyIISWebApplication MyTargetPath
Make sure that MyIISWebApplication is a registered web application within IIS. MyTargetPath defines the path where the precompiled version should be stored. If the target path includes spaces use double quotes to make the command work.
If aspnet_compiler won’t be found add the installation path to the environment variables: