What is someone who is a "problem solver" called?

There is someone that always when there is a problem he says: "No problem it will be OK". We know that we can trust that he will manage and solve this problem.

How do we describe this person? Something like a managabalator person? (Someone who manage things)

The same word. When there is a problem. He can say: "Don't worry it will be {missing word}"

In Hebrew we can say:

• אחד שמתסדר
• יהיה בסדר
• הוא מסתדר בחיים

This is a Hebrew slang. So, I accept slang answers.

By the way, you can think about wizard. "He is a wizard." But wizard solve problem in a magically way. This person just address the issue by using creative ways.

He is a can-do person

can-do, from The Free Dictionary:

Marked by a willingness to tackle a job and get it done: "the city's indomitable optimism and can-do spirit" (Christian Science Monitor).

confident and resourceful in the face of challenges: a can-do attitude

To work with the sentence the OP wrote:

When there is a problem, the can-do person says "Don't worry, can do, no problem".

Or, if using slang, she might say (see Wikipedia):

....no problemo!

Finally, sometimes a can-do person has to say "no can do"; then you know you really have a problem!

I call these people my "fixers". As a manager, I give them hard stuff, and I know they can make something happen.

Since slang is ok, I'll mosey to the urban dictionary:

http://www.urbandictionary.com/define.php?term=Fixer

The person is a problem solver.

a thinker who focuses on the problem as stated and tries to synthesize information and knowledge to achieve a solution

-- vocabulary.com