Often times, the best solution is to simply click the retry launch button. This is especially the case when no error messages are visible on the campaign.

The retry launch button can be found on the intelligence overview tab, to the right of a campaign with errors status.

If retry does not work, try creating a new campaign using the same creative. You can quickly make a new campaign from the launch button within the left navigation.

After making the new campaign, choose 'import from previous" in the top right corner of the ads tab. From here you can quickly re-apply the settings from your previous test and try launching again.

Reach out to your customer support rep or contact us from the live chat button in the left navigation.