The Federation Service encountered an error while loading the trust policy. An exception was thrown during loading of a custom ...

The Federation Service encountered an error while loading the trust policy. An exception was thrown during loading of a custom module assembly. 
Assembly path: %1 

If this error occurs startup of the during Federation Service, the Federation Service will be not be able to start, and all requests to the Federation Service will fail until the configuration is corrected. If this error occurs while the Federation Service is running, the Federation Service will continue to use the last trust policy that was loaded successfully. 

This error may be generated by a non-Microsoft module that is not part of AD FS. 

User Action 
Ensure that the assembly path is correct and that the assembly file has appropriate permissions. 

Additional Data 
Exception information: 
%2