cant play

GAME ALREADY RUNNING

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• Minecraft is already running in this game directory. Starting it again may cause malfunctions or corrupt your saves. To solve this, create a new launch option and edit it to run in a different game directory.

is the messenge give all day.
i unnistall the game and install again by the free copy from mojang,and still that messenge all the time i try play.
i dont log in into other device just in that computer and i cant play.
can someone help pleeeaassee?