Related documents configuration is entirely unclear

First case:

• Start a new 10.2 archetype project.
• Add some features using essentials (eg simple content, news)
• rebuild
• Add Related documents
• rebuild
• Go to configure related documents
• Click select search folder for any document and select a folder
• Press add related documents.
• Notice message saying 'You have added a field to one or more document types...'

Expected, related documents has been added to the document type.
Actual nothing has been done

Second case

• same as above up to configure step
• select check box next to a document type
• select folder
• Nr of suggestions field is red even though '10' seems to be filled in. Cannot click 'Add related documents'

Expected, 10 is default vaule
Actual, 10 is a suggestion and the field is required. Better not to give a suggestion at all.