The last step did not log any message! (Source: MSSQL_REPL, Error number: MSSQL_REPL22037)

We have one publication and in replication monitor we have one error in subscription watch list like below: "The last step did not log any message! (Source: MSSQL_REPL, Error number: MSSQL_REPL22037) Get help: http://help/MSSQL_REPL22037"

And 

1. our sql server version is 

Microsoft SQL Server 2016 (SP1-CU7-GDR) (KB4057119) - 13.0.4466.4 (X64)   Dec 22 2017 11:25:00   
Copyright (c) Microsoft Corporation  Standard Edition (64-bit) on Windows Server 2016 Datacenter 10.0 <X64> (Build 14393: ) (Hypervisor) 

2. product level is sp1.  

Our questions are:

1. how to check the details for this error.

2. If we couldn't do sql server upgrade, is there any workaround way?

Thanks a lot!