deja-dup reports that a file in .cache was missing

Deja Dup ran yesterday and told me there was no space left in "/" for a backup, so I got rid of some downloads I didn't need by putting them in the Trash and emptying it. Today it tried a backup (I have it on a schedule) and said:
Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1412, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1405, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1281, in main
    sync_archive(decrypt)
  File "/usr/bin/duplicity", line 1037, in sync_archive
    loclist = globals.archive_dir.listdir()
  File "/usr/lib/python2.7/dist-packages/duplicity/path.py", line 525, in listdir
    return os.listdir(self.name)
OSError: [Errno 2] No such file or directory: '/home/rajiv/.cache/deja-dup/5543538a1a9cb7b890ab7791a83b4c53'

I saw the file named above yesterday by doing cd ~/.cache/deja-dup and then did ls. Today I did the same and did not find the file. What happened to the file? Is it safe to recover the file from an old backup?