Why my frame freezes when i hit play how to solve it

My problem is that when I hit play button and enter in game view automatically pause button is pressed which I m not able to uncheck and I manually click on the third button to go next frame.
I first encountered it when I imported RPG mecanim animation from unity and when I imported its scene I need to click on the third button eveytime I want to go to the next frame.
Help me.

well you have some errors in your scripts and on the conosole you’ve enabled Pause on Error uncheck that and you’ll be able to play, but the error will be still there