Could you help to solve a friend problem?
We can't creat Sales order documents from CRM documents (Opportunities, Activities and Complaints).
What's wrong? What's missing?
Do you want to create a Sales Order in CRM itself or in ERP?
For both these things you will have different setups:
If sales order in CRM, then you need to check the copy control configuration.
If in ERP, then this is done using Actions as far as I know. So maybe the action settings might be checked.
Hope it helps.