FASTCGI流程最近频繁失败。 请稍后再试一次

We have setup a Wordpress Website on IIS 10 which was working fine. But suddenly it stops working and i got this error

"FASTCGI process has failed frequently recently. Try the request again in a while"

Restarting IIS fixed this problem.

Anybody tell me why this issue has occurred and how we can fix this ?

Thanks