Form W-2 - More Than Eight State and Local Withholdings
1

If you have state or local withholdings for more than eight states, you will need to create another Form W-2 Wage and Tax Statement in the TaxAct program to enter the additional state and or local withholdings. Be sure to select the state and locality from the drop-downs for Boxes 15 and 20 again.

You will not be able to file electronically, rather you will need to file a paper return.