IF NOT seek(alltrim(mpatlastname), ALIAS(), "last_name") > do form pat_add &&do form notfindapppatient > thisform.release() > ENDIF >>>>Correct your SEEK to use existing index tag.
thisform.refresh >>do case >> case .not. isblank(mpatlastname) >> seek alltrim(mpatlastname) order tag last_name of patient.cdx >> if not found() and eof() >> do form pat_add &&do form notfindapppatient >> thisform.release() >> endif >> case mservpatphone <> 0 >> seek (mservpatphone) order tag phone of patient.cdx >> if not found() and eof() >> do form pat_add &&do form notfindapppatient >> thisform.release() >> endif >> case mhlth_card <> 0 >> seek (mhlth_card) order tag health_num of patient.cdx >> if not found() and eof() >> do form pat_add &&do form notfindapppatient >> thisform.release() >> endif >>ENDCASE>>