Eloqua: HTTP 400 Too Many Campaigns to Run the Report

The "HTTP 400 too many campaigns to run the report" error can occur on some Oracle Eloqua entities that CData exposes as tables which connect to Campaign data, such as the Activity_CampaignMembership table.

Oracle's Recommended Solution is as Follows:

There is a limitation based on the number of campaigns that you have on your instance. If you have more than 4,000 campaigns, the report will not show the data to avoid performance issues because this is a heavy request.

If you reduce the number of campaigns, you should be able to see the report again. If possible, we recommend deleting old campaigns that are not being used anymore.