If you are upgrading a Marketing Operations system that is integrated with Campaign and you have existing campaign projects for which you have not created the corresponding linked campaigns, create the linked campaigns before you upgrade to Marketing Operations. Likewise, if you have existing project requests for campaign projects, accept or reject the requests before you upgrade to Marketing Operations.

If you do not link them before you upgrade, then when you attempt to create the campaigns for these projects or accept these requests after the system is upgraded, the campaigns will not be linked properly to the Marketing Operations projects.