Pennsylvania's state government websites are back online after being dark for nearly three hours, but the tax-day outage is prompting a postponement of the filling deadline.
The Monday afternoon outage affected many of the departments under the governor's jurisdiction, including the Revenue Department on the last day to file taxes.
As a result, the department said it won't penalize income tax returns that are filed by Tuesday midnight, a day late.
It said Pennsylvanians were unexpectedly unable to file taxes online for a few hours or get tax forms online or help from its online customer service center.
The outage began around 1:30 p.m. and was resolved at about 4 p.m. Officials couldn't say why it happened, just that it wasn't triggered by a cyber-attack.