Getting a online error and printer won't print.

Without knowing what online error, it's not easy to diagnose what happened and how to compensate.

Anyway, try checking the printer cables to ensure they're connected and properly seated. Verify that the paper tray is correctly loaded and the Toner light is OK.
Verify that all printer covers are flush and closed, and check that the printer is correctly connected at the software level (i.e., in Control Panel -> Printers -> (ML2010) -> Right Click -> Properties -> Ports, you have the proper USB socket selected).

Try plugging it in another USB port. Did it stop working, or did it never work? If the latter, then the driver could be incorrectly installed; try removing it and installing again.