SQL Server 2012 / 2014 Merge Issue - Cannot insert duplicate key row in object 'dbo.sysmergepublications' with unique index 'nc1sysmergepublications'.

We have a number of customers running SQL 2008 R2, 2012 and 2014 that we have set up with merge replication between their corporate office and their retail stores. The stores are republishing to the registers. We keep getting this error from time to time:

Cannot insert duplicate key row in object 'dbo.sysmergepublications' with unique index 'nc1sysmergepublications'. The duplicate key value is (b10a32a6-f715-4ab5-8499-b151f5059121).

This is wreaking havoc with our help desk.  I thought this problem was fixed by Microsoft with SQL 2005 or 2008.  This has become a major issue.  Does anyone have any ideas? 

1.  What do we need to do to fix it.

2.  What do we need to do to stop it from happening again?

Thanks for any input!