Sudden "No Battery Available" when previously battery seemed fine.
My battery seemed to be working fine; good, reasonably long lasting charge. Then yesterday, with the computer on, when I detached the AC adapter cord from the Macbook Pro, the computer immediately went dead off... lights out! I can reboot the laptop with the AC adapter attached, but the initial boot up screen showing the Apple logo is dark gray with the logo barely visible, and when fully booted the clock is no longer the correct time (an alert tells me to fix the clock time), and the battery icon in the uppermost top right screen bar shows an empty battery with an "X" in it. Click on the battery icon and it says "No Battery Available". The attached AC adapter light glows a solid green, as if the battery were fully charged.
My question at this point is; do I just need a new battery, or is there something else more sinister that's gone awry that has to do with not being able to access the still-good battery?