Twitter is Not Allowing to Switch Old Twitter

Old Twitter is now old for me... Today, I switched to "New Twitter" for giving a try and again when i was switching back to "older version", It showed me an error like this..

403 Forbidden: The server understood the request, but is refusing to fulfill it.

Twitter started its process for destroying old twitter.... welcoming "New Twitter".

Tips: 
If you want to use Old Twitter for more period of time, then never switch to New Twitter. Keep on using the older version till the last date.