I had spent several days searching for the cause of this error (The schema script 'TableName_5.sch' could not be propagated to the subscriber) in a merge replication issue on SQL Server 2014, finally I discovered the problem by trial and error. I found lots of hits when googling this error message but none related to my actual problem, so I determined to document it for anyone else who may have similar problem.
My publication includes tables for 2 schemas but these tables have the same name i.e. "dbo.Customers" and "schema2.Customers" when setting up the articles in the publisher UI the tables they are listed as "Customers (dbo)" and"Customers (schema2)", and all appears to be okay.
But when replication starts it appears the .sch file in the snapshot folder is only named with the table name "Customers" and the schema portion of the name is dropped. This caused me lots of trouble, it wasn't until I remove the articles for all the duplicate table names that this error disappeared and replication started working again. Also added to the elusiveness of this was the entire replication setup was scripted so I had not opportunity for the UI to offer any warnings. So beware if you are replicating table articles with same names across multiple schemas. I hope this can help someone else avoid days of trial and error.