Unable to add reply to joined primary threaded post = SQL error


Forum thread with replies is joined to existing, long running thread with many replies shown in hierarchical view. User with administrator role attempts to post a reply to the formerly top level thread post (now a reply) and generates the following exception:

System.Data.SqlClient.SqlException (0x80131904): Cannot insert the value NULL into column 'Level', table 'Verint11.dbo.te_Forum_ThreadReplyHierarchy'; column does not allow nulls. INSERT fails.

If the same user attempts to reply to an existing reply of the formerly top level thread, there is no issue.

Any thoughts on how to resolve or avoid this?