When adding a Server Termbase to a Project the following error occurs:

A connection to SDL MultiTerm Server ... could not be established. Could not load file or assembly 'ICSharpCode.SharpZipLib, Version=1.0.0.999, Culture=neutral, PublicKeyToken=1b03e6acf1164f73' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Please go to C:\Program Files (x86)\SDL\SDL Trados Studio\Studio15  and search for SDLTradosStudio.exe.config



Right click on the file, open it using Notepad++ with Administrative rights and follow these steps:

1.  Go to the end of the file
2.  Before the last  </assemblyBinding> please copy the following:

<dependentAssembly>
        <assemblyIdentity name="ICSharpCode.SharpZipLib" publicKeyToken="1b03e6acf1164f73" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-1.2.0.246" newVersion="1.2.0.246" />
</dependentAssembly>

This is the way the file should look:



 

You are trying to connect to a Server termbase located on a GroupShare server.

 

In this article you have the compatibility description between different versions and products of SDL:
https://gateway.sdl.com/apex/communityknowledge?articleName=000001175