Null pointer exception

[Bhawak]

Find the stack trace:
java.lang.NullPointerException:
at np.com.nirab.nepalideveloperutils.BSCalender.NepaliDate.getMonthString (NepaliDate.java:193)
at np.com.nirab.nepalideveloperutils.BSCalender.NepaliDate.init (NepaliDate.java:164)
at np.com.nirab.nepalideveloperutils.BSCalender.NepaliDate. (NepaliDate.java:32)
at org.kathmandulivinglabs.sajhasabha.Fragment.IssueDetailsFragment.parseDateToddMMyyyy (IssueDetailsFragment.java:1056)
at org.kathmandulivinglabs.sajhasabha.Fragment.IssueDetailsFragment$7.onResponse (IssueDetailsFragment.java:650)
at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run (ExecutorCallAdapterFactory.java:68)
at android.os.Handler.handleCallback (Handler.java:751)
at android.os.Handler.dispatchMessage (Handler.java:95)
at android.os.Looper.loop (Looper.java:154)
at android.app.ActivityThread.main (ActivityThread.java:6776)
at java.lang.reflect.Method.invoke (Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1408)