close sbo. go to c:\(your program files)...\SAP\SAP Business One\Conf
copy the file b1-local-machine.xml
now, go to c:\(your program files)...\SAP\SAP Business One DI API\Conf
and paste the file you copied before. It is going to replace another file with the same name. Say ok and replace.
Login into sap, now the add on should work...