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12" MacBookPro late 2012, OSX 10.9.5
Something is wrong with the Finder. When I try to open a new window one pops up, but the interior is the color of the background, nothing inside, and it reflects the image of anything that is dragged over it:
Those windows start out blue like the background, but are grey here because to take a screenshot I had to drag the grey rectangle over the finder window. They close just fine.
To open any working window I have to open Terminal and type
killall Finder, but this solves the problem for a short time. (Sometimes the space of only one window opening.) Also, the desktop does not reflect saved files there until I restart the Finder, and I cannot manipulate anything on the desktop when the Finder has crashed.
A very small amount of water was spilled on it (over the battery and speaker) awhile ago, could that have caused this? What could be wrong? I've seen similar issues posted online involving software installation, but can't link any new installations to the problem. How can I resolve this?