A folder with question mark appears when I turn computer on

[iMore Question]

When I turn my macbookproa1502 on a folder with a question mark flashes on the screen and I can't do anything else

 

[anon(9602380)]

Welcome to iMore.

This is an indication that your MBP is looking for its system software and can not find it. Here is a guide by Apple on what you can do to hopefully solve the problem.