At least seven states cannot print ballots yet because of unresolved questions about the ballot. Here is an article explaining that Connecticut must wait until the State Supreme Court decides which party should be listed first on the ballot.
New York can’t print any ballots until the Independence Party chooses a presidential candidate, which it will probably do on September 20, the New York state deadline for that.
At least six Colorado counties can’t print ballots until a federal court decides whether bar codes should be on ballots.
Pennsylvania doesn’t know yet for sure whether the Libertarian statewide candidates will be on the ballot or not. In Pennsylvania, when a challenge process is still pending, it is customary for some ballots to be printed with the challenged candidates listed, and then to mark them off if the challenge goes against them.
New Hampshire won’t print any ballots until the Ballot Law Commission decides whether Virgil Goode should be listed as the Constitution Party nominee for President. That will be decided by the Ballot Law Commission on September 20.
Kansas won’t print any ballots until the challenge to President Obama’s qualifications is resolved.
This list isn’t necessarily complete, and does not try to deal with Michigan. Federal law requires overseas absentee ballots to be mailed no later than September 22.