VBA code: A Sub() module to CALL another Sub ()

I think you should change the call to CheckCells from the SaveAsPDF routine

currently you have

Sub SaveAsPDF()
    
Call Checkcells.emptycell
    
    Dim fname As String
    Dim wb As Workbook

replace the highlighted part by

'# declare
    dim returnval as boolean
'# call the routine to check if all cells have been filled, if not returnval is returned as TRUE
    call emptycell(returnval)
'# exit the routine (i.e. do not create the PDF) if one or more fields were foudn to be empty
    If returnval then 
        exit sub
    end if