You were trying to install ShortPoint on SharePoint Server 2010 or 2013. And then the installation stops and show this error:


Error: Cannot add the specified assembly to global assembly cache: Newtonsoft.Json.dll.



Cause

During the install, the process managing the install was unable to deploy a required assembly [DLL] to the global assembly cache [GAC]. This happened because you have already the same dll file installed and our solution is trying to add newer version of the same dll.


Resolution

Remove the dll manually and run the installation again by executing the following command:


gacutil –u Newtonsoft.Json.dll 

gacutil –u Newtonsoft.Json.dll


Important

Important: Best practices for successful installation