You cannot close the activity Confirm Milestone: Solution Accepted in the test system.
Reproducing the Issue
- Go to Business Configuration work center
- Go to Implementation Project view
- Select the project and open activity list
- Open the activity Confirm Milestone: Solution Accepted
- The tick box for closing activity is grayed out
In a test system, certain activities including "Confirm Milestone: Solution Accepted" are disabled, because you cannot go live with a test system. You have to maintain these configurations in productive system and go live in that system.
Perform this activity in the productive system
KBA , LOD-CRM-ACC , Account , Product Enhancement