Can't insert activities into CRM365

[#1]

We are in the process of upgrading from  Microsoft Dynamics CRM 4.0 to Microsoft Dynamics 365.

External account is configured  and I am able to synchronize entities from CRM to Adobe campaign. 

Next I am able to export contacts and/or leads form Adobe campaign to CRM.

But when I try to insert an appointment, Email or Campaign response, I receive an error:  Error while inserting the object with local ID '399974922', cause: 'An unexpected error occurred.'

By trial and error filled the minimum of required fields, untill the point no errors on missing data are reported  in the logs. Resulting in the unexpected error (http error 500 is logged prior to this message.)

Generic CRM connector:

And when I use the Specific Dynamics connector (this is based on a simple synchronization: import responses from CRM to campaign via connector, update subject and local change dates and synchronyze these changes back to CRM):

I get this error:

Error while updating object (local ID: '400048217', remote ID: '691CEA8E-2FF5-E711-A82A-000D3AB4B471'), cause: 'When updating an activity, regarding object id has been provided, but regarding object type was missing'.

adding/removing regardingobjecttpecode does not effect the outcome.

Can't find anything when searching the net regarding these errormessage(s).

Does anyone recognize this ?

Kind Regards

Menno.

[#2]

Dear Menno,

I had done what you mentioned and it worked like a charm, except for the PhoneCall.To and PhoneCall.From. These fields seems to work in another particular way. Please take a quick look at this: Link directly from microsoft and this link, a blog that I found that the guy kindly simplify the process but no solution.

Well, I belive the logic would be:

Pass the activity CRM ID to activity party and specify the parties, mentioning 1 to Sender and 2 to To field. Does that make sense? Do you mind helping me come up of what of doing this?

Thank you in advance