Ghost Solution Suite 3.0 - Unable to install trial

I am trying to install the GSS 3.0 trial on a Windows Server 2012 R2 VM to evaluate before possibly upgrading our 2.5 server.  However I get the following error message (see attached screen shot):

"The license file you specified is not a valid Ghost Solution Suite license.

Please select a calis license for this product."

I have not been provided with an slf file for the trial but the installer says that one is not needed, just to leave the license file field blank to 'use Trial license'.

Do I need a trial slf file (if where do I get it from) or am I missing something?

Thanks