Good morning.  We import our payroll checks from Checkmark into DBA.  After having posted payroll in DBA,  I found I had to recalculate a check.  The new check has been imported properly.  How do I void the first check in DBA - as Void AP check does not apply?

Can't just delete it, you need to also reverse all the GL postings.  Since your actual payroll reports will be coming out of CheckMark, I suggest a GL-B CR (Cash Receipt) entry to put the money back in the bank and reverse the GL postings.