In fact, I have contributed NO answers that I know of and the 6 questions I have asked over the past year have ZERO answers.
In reality, you've posted a total of three answers since your account was on Ask Ubuntu. All three are deleted, as a direct result of review queue votes, and flags against your posts. (Deleted answers still count as answers!)
The three answers that were deleted do not fit into our criterion of "answers". In all three of your answers, you either are saying "I have this issue too" (which is not an answer), or are asking new questions which are basically the ones you already asked on the questions you had posted those answers on. If such questions are substantially different, you should post a new question, and if not, you should not post an answer to just state you're having the same issue and try and add different debug data (which may be relevant only to you).
As was already posted, the Help page indicates there are a lot of automatic filters. All of your posts have been delete-recommended voted in the Low Quality queue, and subsequently deleted as "Not an Answer". The system acted as a result of this, and answer-banned you (meaning you cannot post answers).
From the same help center page linked already in another answer here, you can get information about how to resolve the problem. The first two in the bullet-points are relevant here, as is the whole section I just copied in:
##How can I get out of an answer ban?
The ban will be lifted automatically by the system when it determines that your positive contributions outweigh those answers which were poorly received.
###Stack Exchange cannot lift answer bans by request.
The only way to end a posting block is to positively contribute to the site; automatic bans never expire or "time out". Begin by fixing your existing answers; do not just post the same answer again or delete all of your existing answers. All answers are expected to be useful to future visitors, in addition to the original asker, so keep the following tips in mind when improving your answers:
Answer the question. Do not post an answer simply to say "thanks" or "I'm having this problem, too"
Do not post follow-up questions as answers. Ask a new question instead.
Use correct spelling, punctuation, and grammar to the best of your ability.
Provide context for links. Link-only answers are not good answers.
For additional guidance, see "How do I write a good answer?"