That would have been caused by exactly the same thing that caused the backups to fail, the database being in single-user mode and an existing connection to the database, hence the reorganise would not have been able to connect and would have failed.
Once you switched out of single-user mode, the backups and reorganise could run successfully.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability