The assembly combination consists of version, culture, and public key tokens. ASP. NET first searches the application's private Bin directory for the assembly DLL, and then searches the system assembly cache for the assembly DLL.
The add element adds an assembly reference to use during compilation of the dynamic resource. When you compile each code module, ASP. NET automatically links the assembly to the resource.
the value of the add element is the assembly name, not the DLL path. asp.net finds the assembly name to find its physical DLL location. %systemroot%\microsoft.net\framework\ version\). " > You can also optionally specify an asterisk (*) wildcard character to add each assembly in the application's private assembly cache, which is located in the application's \ bin subdirectory or the. NET Framework installation directory (% Systemroot%\microsoft.net\framework\ version \).
Reference: Https://msdn.microsoft.com/zh-cn/library/37e2zyhb.aspx
Where are the elements of the compilation assemblies add in the ASP Web. config file