Switchover in 12c

Hi Friends,

Am testing switchover 12c new feature.

When i use verify option it is working but during actual run phase it failed with error with synchronization issue(I do not have archive log gaps, not even single and using real time apply). However Oracle provided FORCE option in that case.

But it doesn't working for me, i tried with several options but it didnt worked at all.

If any body knows or tested, can you please share your experience. This is the document am referring to  Performing Role Transitions Using Old Syntax  

SQL> select db_unique_name,database_role,open_mode from v$database;