Export BPMN : error on manual and service task symbols

Hello,

I work on ARIS 9.7 with models and symbols derived from BPMN 2.0  (BPMN 2.0 process diagram).

I apply the function "Export BPMN diagram as a BPMN file..." to some models, and it generates warning on manual tasks and service tasks symbols for which I'd like to have explanations.

Here an extract of the diagram with the warning on the manual task

Here is a capture of the full diagram (I've made cuts but the flow should be understandable) with the warning on the service tasks

Does anyone know what ARIS is expecting for these symbol in order to validate the BPMN export ?

Thanks,

Fabienne Rosec