Error: The referenced assembly is not installed on your system


When installing the AuthAnvil Web Logon Agent on a 64 bit server, the agent just blocks the web site with a 500 error. Also, the Windows event log contains the following error:

Generate Activation Context failed for \\?\C:\Program Files\Scorpion Software\AuthAnvil Web Logon Agent\AAWebLogon.dll. Reference error message: The referenced assembly is not installed on your system.


The Microsoft VC++ Runtime Libraries (v9.0) are not present.



Download and install the "Microsoft Visual C++ 2008 SP1 Redistributable Package (x64)". If that does not resolve the problem, download the Dependancy Walker ( and load the AAWebLogon.DLL to see what other dependancies may not be currently installed.

Note: You should ensure you have the 64bit versions of these DLLs installed.


Applies To

AuthAnvil Web Logon Agent v2.x, AuthAnvil Web Logon Agent v3.x



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