Not allowed to load assembly from network location

I had the same problem, when trying to load a DLL on a local drive which came from a ZIP from the internet. The solution was to unlock the ZIP in its file properties. Finally, extracting the DLL again and now it loads without the error. No need to change the machine.config.

Adding the loadFromRemoteSources switch to machine.config solved the problem.

MSDN

The loadFromRemoteSources element specifies whether assemblies from remote sources should be granted full trust.

Example

<configuration>
    <runtime>
       <loadFromRemoteSources enabled="true"/>
   </runtime>
</configuration>

You can find machine.config here:

32-bit

%windir%\Microsoft.NET\Framework\[version]\config\machine.config

64-bit

%windir%\Microsoft.NET\Framework64\[version]\config\machine.config