ABIS Null Reference exception Error

I am using ABIS and encountered another issue while using this.
I tried to put my finger expressions on, however, an error message appeared on the screen that states:

Error:
System.NullReferenceException: Object reference not set to an instance of an object. At Neurotec.Samples.LongTaskForm.RunLongTask(String title,DoWorkEventHandler callback, Object arg, Control ctrl) in C:Usersjeff.DOMAIN1DownloadsNeurotec_Biometric_4_2_SDK_2011-12-06Neurotec_Biometric_4_2_SDKSamplesBiometricsVBAbisSampleVBCommonLongTaskForm.vb:line 37 at Neurotec.Saples.Fingers.AddFingerprintsPage.bwCapture_DoWork(Object sender, DoWorkEventArgs e) in C:Usersjeff.DOMAIN1DownloadsNeurotec_Biometric_4_2_SDK_2011-12-06Neurotec_Biometric_4_2_SDKSamplesBiometricsVBAbisSampleVBFingersAddFingerprintsPage.vb:line 1303
I hope to get some concrete advise to resolve this problem.
