Error: (weing765) Adjustment posting: no price for item xxxxxx available

Solution

1. Check if price is NOT 0.

2. You could set up Price 0 available in the Configuration Wizard. 
But it is highly recommended that you don't allow Goods Receipt with no price, so you can avoid error just like in this case where the materials were not issues yet.
 
Go to: Configuration Wizard > Production > Valuation and booking of assembly > Booking.
Check "Allow booking without prices".