If you've made a change to the federal individual return but did not open the Maryland return to update it, the Maryland return will reject with the following code:
Reject Code: Form502-01710-010
Line 40 Total Maryland and local tax withheld - Must equal Total Maryland and local tax withheld from all W-2s, W-2Gs, 1099-Rs, 1099-Gs, 1099-MISCs, 1099-Bs, 1099-DIVs, 1099-INTs, 1099-OIDS, 1099-K and 1099-NECs.
Generally, to correct this reject in TaxSlayer Pro simply open the Maryland return, exit, and retransmit the Maryland return "State only".