Problem solved!
Private Sub btn_OpenUTI_StageTwo_Click()
On Error GoTo Err_btn_OpenUTI_StageTwo_Click
Dim stDocName As String
Dim stLinkCriteria As String
stDocName = "UTI_Main"
stLinkCriteria = "[patID]=" & Me.patID
DoCmd.OpenForm stDocName, , , stLinkCriteria...