paypal - Paypal MPL iOS Error : internal server error in iOS

Question

I did Paypal MPL integration in my project.after I wrote the the below code in appdelegate

[PayPal initializeWithAppID:@"APP-80W284485P519543T" forEnvironment:ENV_SANDBOX];

After I run the code I got the following error

checking Error********************
Posting Error: 2147483647

and I got the alert "Internal server error".

I wrote the above code in XCode 6.2 and running device iOS version is 8.2.