NW04s ABAP Install Step 17 - Loading of SAPSSEXC error

I am struggling to install the latest speak preview nw04s for ABAP. In step 17 - import ABAP - I cannot get past this error:

in file import_monitor.java.log, I see the follwoing:

Loading of 'SAPSSEXC' import package: ERROR

Import monitor jobs: running 0, waiting 1, completed 16, failed 1, total 18.

in file import_monitor.log, I see a java exception at

com.sap.inst.migmon.LoadTask.loadPackage.....

....etc...

Can anyone please help?

thanks