STEPS:-
1) Install titanium backup from play store.
(Root is required for this app).
2) Open it and give superuser permission..
3) Tap on switch profile in bottom right
corner..
4) Here you have to create two data profiles
with any name (eg. All and whatsapp2).
5) Again tap on switch profile and select all
(main profile).
6) Now go to backup/ restore tab on top.
Locate whatsapp.
7) Tap on whatsapp then swipe right for
special features..
8) Tap on enable multiple profile for this
app.
9) Confirm any prompt. This will store your
current whatsapp profile to data profile 'all'.
10) Now again go to overview tab and tap on
select data profile and select 'whatsapp2'.
11) Now go to whatsapp and you can see the
first installation window. Register your
second number there. And you are done..
12) For switching between numbers use
titanium backup and switch data profiles..
NOTE: You can use more than two numbers
by this method.. ! So use it as soon as soon it
will be fixed.. Any problem.. Just Comment