It's not possible to set default Location for objectrelationlist content field type.

Steps to reproduce:
1. Login as admin
2. Go to Admin -> Content Type
3. Select "Content"
4. Start creating new Content Type
5. Enter Identifier ("TestIdentifier")
6. Add new field: "Content relations (multiple)
7. Expand the field settings and click "Select location"

Expected:
UDW is opened.

Actual:
UDW does not open. Following error is visible in console:

Uncaught SyntaxError: Unexpected token u in JSON at position 0
    at JSON.parse (<anonymous>)
    at HTMLButtonElement.openUDW (0cf5726.js:73)