Backup failed

[sma3730]

Here is the error message which keeps popping up:

“The backup disk image “/Volumes/TimeMachine/Steven Aasen’s MacBook Pro.sparsebundle” is already in use.”

The drive has been backing up two Windows PC (one W7 and one W8) as well as my MacBook Pro.  Yesterday I began getting (periodically) the backup fail message which I put in quotes above.  

How do I fix this?

Thanks,

Steve

[John012]

You might want to perform a powercycle on the My Book Live and restart the computer.