Why do we get an opportunity to answer our own question, now a days? Is it due to some technical problem? Is it okay?

You get that opportunity because someone thought it was something needed.

It has been allowed since March.

It is OK to post the answer your question if you find the answer you were looking for elsewhere so others can view the right answer.

You should not use the Answer feature to add details, that should be done using Edit /Update.

You don’t get points for answering your own question and you can’t choose yourself as the Best Answer.

This is the Staff blog about it http://yahooanswers.tumblr.com/post/79509311376/an...

We've been given the opportunity to answer our own questions so that if we find an answer later that is better or more up to date than what we have and we wish to add it for the benefit of others, we can. The stipulation here is that we have to actually answer the question, we can't use it to comment on answers, ask other questions, add details, chat with other users, etc. If we do, we can be found in violation of the CG as a non answer.

That said, when someone answers their own question, they don't get the points for it nor does the "Award Best Answer" button appear under their own answer, so they can't award themselves BA.

The idea is that if you find your own answer, which is better than those you were given here, you can add it for the benefit of others who might look at your question later when they are seeking help.

You've been able to answer your own questions ever since they got rid of voting.