Error when upgrading SQL Server from 2012 (sp3) to 2014
Run this 

EXEC  master.dbo.xp_instance_regread
 N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer',N'BackupDirectory' 

to see what your default backup directory is set to.

This can also be viewed in Management Studio by right clicking on your instance, selecting Properties and going to the Database Settings tab. It will be near the bottom under Database default locations. If your default backup directory is set to 'H:\MSSQL11_MSSQLSERVER_Backup_Dir', changing it will help.