Infusionsoft gets stuck while trying to publish a campaign

I will click the Publish button and the system moves through all the steps, “analyzing campaign”, “checking email timers” and what have you, then goes back to “analyzing campaign” and stays there, with the wheel turning, never bringing up the final checklist to show whether there are errors, so I can’t actually publish my campaign. Why is it getting stuck? Am I doing something wrong, or is this the system? I have successfully published campaigns, and recently, and I have no idea what’s going on.