I am not sure why the mapping is giving the error "Task has some invalid columns mappings".
Can you please help, please check below screenshot
Hope you are doing well.
The mapping issue in your case is related to the fact that the synchronization package works in both directions: from to Source -> Target and also from Target -> Source, but mapping only for one direction is configured in your package.
Once the mapping is configured from Source to Target, you need to select Target to Source tab and configure mapping in the opposite direction. Please see the screenshot for your reference. Additionally, please follow the guide on how to create synchronization task for more detailed information: https://docs.skyvia.com/data-integration/synchronization/how-to-create-synchronization-task.html
May I please additionally clarify the exact scenario you need to implement?
If you need to transfer data in one direction, for example from Pipedrive to ActiveCampaign, it is better to use Import Package. If you need to load data in both directions, then please use the Synchronization Package.
Looking forward to hearing from you.
Kind regards, Nataliia