There are a number of potential causes, including:
From the Channels tab, select the Manage Account button and search for the account and campaign name and make sure it shows as Linked. If it is not linked, link it in. Also note if the option to Automatically link new campaigns is not selected, then campaigns created in the publisher will not be linked into the Platform automatically.
If you do not see the campaign in the list, check the publisher to verify if the campaign is deleted. If so, you can reactivate the campaign (depending on the publisher) and sync it down. You cannot reactivate Microsoft campaigns.
If the campaigns are missing or do not show as already being linked in the Linking Wizard, then there are two options to either delete or rename the campaign from the publisher or the Platform:
Once you have solved the duplicate campaign issue as outlined above, you may notice that the affected objects may still show the Parent is in an invalid state error and be in the To be resent status. To resolve this, you can go to the Activity Log and re-push the objects to the publisher manually. If this doesn't work, you will need to re-upload the original bulk sheets for these objects.
For more information about these errors, please read our help article.
There may be times that one or more of your campaigns do not appear when you go to the Channels tab despite the fact that they exist in the publisher interface. Choose a publisher account, and click Edit. If you're sure that these campaigns have not been deleted within Google Ads or Microsoft Ads, you can follow these steps to try to fix this issue: