Odoo 10: Error: "You must set a Vendor Location for this partner" in internal purchase orders in multi-company setup

I encounter an error in internal purchase orders between the two companies in a multi-company setup. When I try to accept a purchase order I get the ERROR: "You must set a Vendor Location for this partner" and the purchase order remains a draft (RFQ). However all other purchase and all sales orders work properly! Let me explain in more detail:

Company A: the initial company configured before enabling the multi-company option

Company B: the second internal company configured after enabling the multi-company option

Company C: external customer or supplier

Only the purchase orders with company A as supplier and company B as customer fail with the error, all other purchase and sales orders work!

That means:

• The reverse with company B as supplier and company A as customer works
• All purchase orders with an external company C work (for both companies A and B)
• All sales orders work with all possible customer/supplier combinations (A-B, B-A, A-C, B-C)

I tried to carefully review the storage locations but can not make out any difference between company A and company B.

Questions:

• Does anyone have an idea what could be wrong or what setting I could try to change?
• How could I try to isolate the error?
• Could someone be so kind telling me how I can try to help myself? Where can I see or enable error logs? Where can I see more detailed output or parameters to try to understand what is triggering the error.
• Purchase and sales orders had been carried out for company A before enabling the multi-company option. Could this be the cause? Do I need to start with a fresh empty database (no previous orders), when enabling the multi-company option?

Any help or hints would be highly appreciated!

When we are work with multi company and company partner as suppler or customer then we must do location configuration in partner.

In purchase order creating process, when picking is creating then system is setting location_id based on property_stock_supplier field.

In Sales Order creating process, when picking is creating then system is setting location_id based on property_stock_customer field.

This may help you.