OneDrive for Business is updated frequently. If you come from the article Fix OneDrive sync problems, see Is the library configured to be available offline? to begin at the next step. Update OneDrive for Business to the current release

If you are using OneDrive not OneDrive for Business, and you encountered sync issue, you can look for the solutions in Fix OneDrive sync problems. To determine which OneDrive sync client you're using, see Which OneDrive sync client am I using?