I have integrated AEM 6.5 and Target successfully through IMS and legacy Target cloud service. I created an activity on AEM and pushed it to Target. I am able to see the activity in AEM. When I open the page either in publish or in author with wcmmode disabled, I got the following error
This was happening because for some reason, another offer (which was configured to some other page) was being resolved on this page. Hence nothing was displayed. I deactivated the old offer and then the default content was displayed. I still have problem with offer resolution.