Cannot open source input file "network-socket/nsapi.h" : No such file or directory

[bharat_707 (Bharat Gopani)]

Hi
I am using arm Mbed IDE for nRF51-DK platform.
But now we are facing following compile time error,
Cannot open source input file “network-socket/nsapi.h” : No such file or directory.

Can anybody please advice for the same.