Fetal error. The session was terminated

I encountered with this error and i reinstalled the R and R studio but the problem didn't solve.
Could you help me please?

under what circumstances do you face this error ?

Thanks for your answering. After I ran a scrip.
Also all of my packages got deleted.

if it doesn't happen when you run other scripts, then it must be a problem in your script...

I can't run another script at all. Because of this error, my R studio has got inactive.