SoftwareSerial error
This error means, that there is library overlapping on a vectors. To solve this error, you need to modify your Library file :

STEPS :


Remove the Softserial Library 
Download AltSoftSerial library
if you have shield then you need to replace AltSoftSerial in place of SoftwareSerial in both .cpp as well as .h files.
Import AltSoftSerial library in place of SoftwareSerial in the sketch.


Execute .