Replication triggers greyed out

The options under File > Preferences > Replication > “Other replication triggers” are greyed out. The same options under the Schedule replication button on the replication tab are greyed out. I can change the options if editing the location document. Why are these greyed out? Is there a permission setting or other that needs to be in place for these options to be available?

Thanks in advance.

Subject: Answer found

Not terribly intuitive but the options are not available until one or both of the priority replication schedules is enabled. The problem, however, is that when you do this through File > Preferences to have to enable the scheduled replication and then click OK to set the option. Then go back to File > Preferences for the other triggers to be available.

You can also go to the replication tab and access the schedule. But you first have to enable the replication schedule under the Schedule button and then go to Set the replication schedule.