This may be some of the Reason. without a Tax Advisor looking at your
Return we wouldn't know because we didn't make the Entries.
If you received wages that are taxable by a State, the State
may be entitled to a certain amount of annual tax total that your
employer may not have been deducting enough each payroll period to cover
it.
This is the simplest scenario. For anything more you'll need to provide more information.
You owe state taxes because the state tax calculated for your
state income is more than the state taxes that you had withheld.