This is not an 'archive' package for distribution that is why it is not working the way you are expecting hence you are seeing an error.
Below are the steps on how to deploy this:
To install the Service Desk adapter:
1. Download the sdsync.zip file from the Nimsoft internet archive or Downloads section of the Nimsoft support site (http://support.nimsoft.com/).
2. Unzip this file into a subdirectory of the cmdbgtw directory called sdsync, as in this example: probes/gateway/cmdbgtw/sdsync
3. Next you must configure the CMDB Gateway probe to make use of the Service Desk synchronization adapter.
does not conform to the Nimsoft package format