I can see many of the great indicator out there have been lost or became history or became obsolete.
I believe that those who coded many of those great indicator have exerted a great time, effort and some time money to come up with such great product for free.
In return MQ4 does nothing to preserve such great work. They just upgrade their engine and left behind a great heritage of indicator without even considering updating them. What a waste!
They should review every indicator code and certify it for overall performance and reliability to save their software from not working or crashing due to bad or not updated coding.
They just do not respect those huge efforts exerted. They should have either maintain certain level of backward compatibility or upgrade those indicator themselves and make them comply with the new version of their software. Unfortunately None is done.
As a result many of the free indicators has been taken care, updated, improved by some coders here or there and then got commercialized!!!