To witness the problem, perform these steps:
1) Go to Service Level Mgmt > Contracts
2) Edit a Contract
3) Select All Metrics, Add New > Contract Contractual Section > KPI
4) Go to the Registration tab, Add New
5) Select Metric, Next
6) Click Add and select any existing Metric before clicking OK.
7) The metric doesn't populate the dialog, and any attempt to click Next errors because the field is still empty.
This error is fixed by 18.104.22.168.8; if you require the patch please contact Support.