Which Operating System you are using ?
Which version of Adobe Captivate 4 are you using, 4.0.0 or 4.0.1 ?
If you using 4.0.0, try installing Captivate 4.0.1 update from here :
Can you please downlaod -- Download the QuizBusRules and BusinessRules DLL from -- http://kb2.adobe.com/cps/870/cpsid_87095.html
Download the Dlls and Copy and Paste them Directly to C>Program File>Adobe>Adobe Captivate 4>