For one thing that’s not the location of the sandbox SERVER. What you’re looking for is under the ME installation path like:
C:\Program Files\MyEclipse 6.5 Blue\myeclipse\eclipse\plugins\com.genuitec.eclipse.easie.tomcat.myeclipse_6.6.0.zmyeclipse660200810\tomcat\lib
And I don’t see the SSI jar in there. So step #1 would be to get the appropriate jar and put it in the right lib directory.