You are receiving the error message in Act4Advisors 2.0 because you are missing the query files.
Download and extract to C:\Program Files\Act\Query
http://downloads.act4advisors.com/Query.zip

Or you can use the Important Dates Generator
You should install the important dates generator. This will allow you to do the report you are looking for. See pages 53-55 in our manual about the important dates report.

Close ACT!
Download and Install:http://downloads.act4advisors.com/Impdates.exe

Act4Advisors 2.0 Getting Started Guide:
http://downloads.act4advisors.com/a4a3docs/a4amanual.pdf
(manual- read pages 53-55)

An illustration of the important dates generator:
http://software4advisors.com/demo2/demo/importgen.htm

Act4Advisors
http://software4advisors.com 
Allied Financial Software, Inc.