Failed to exclusively access backup

I am trying to delete versions of a backup job but keep getting

Failed to exclusively access backup during consolidation

More information about this error and solutions may be available online in the Acronis Knowledge Base.
To access the online resource manually, enter the event code at: http://kb.acronis.com/errorcode/
Event code: 0x00640232+0x01E50010+0x01E50001+0x01E5001F+0x01E50006+0x01E50017+0x00040014+0x0000FFF0+0x80070020

I have upgraded to the latest version of 2014

Any Ideas to a fix ?

thanks