I have personally encountered such problem and I also searched all over the internet to find some solution for this problem. I finally found 2 solutions for this problem and both of them worked for me. So its time to share them with you, I hope it will fix your problem too.
First Solution: Go to this location C:\Users\Admin, in this case replace admin with your PC user name. You will see .gradle folder. Simply delete it and restart your android studio. The Android Studio will generate new .gradle folder on restart and this might fix your problem.
Go To File -> Settings -> Compiler (Gradle-based Android Projects).
Change the VM options to -Xmx512m -XX:MaxPermSize=512m and restart your Android Studio.
If I find more solution regarding this problem, I will add them here. For now, you can try both of them.