What caused my rdiff-backup failure and how can I resolve it.

[qx6uwumzvv]

CrystalDiskInfo is reporting that a couple of the S.M.A.R.T attributes for one 
of my hard drives have changed cause the health status of the drive to switch 
to "Caution".  Fortunately the Windows 10 drive test doesn't report any errors 
and I haven't had any operational problems yet.  I'm already doing 
rdiff-backups of all the "critical" content on the drive, but but there is 
bunch of other less important content so I tried to do an rdiff-backup 
(downloaded as rdiff-backup-2.2.2.win64exe.zip) of the entire drive to another 
larger drive that still has plenty of free space so I can try to get the drive 
to reallocate the bad sectors or restore the contents to a replacement drive.  
Unfortunately, rdiff-backup reported an error followed by a warning 3 times, 
then a backtrace.  At that point it appears rdiff-backup stopped and didn't 
complete backing up all the files..
The errors all look similar to (the paths are quite long, so I've elided them)

ERROR: Exception '[WinError 3] The system cannot find the path specified: 
b'E:/Backup of Data Volume/.../rdiff-backup.tmp.4795' -> b'E:/Backup of Data 
Volume/.../perl-Test-Reporter-Transport-Metabase-1.999010-3.tar.xz'' while 
renaming from path E:/Backup of Data Volume/.../rdiff-backup.tmp.4795 to path 
E:/Backup of Data 
Volume/.../perl-Test-Reporter-Transport-Metabase-1.999010-3.tar.xz

and the warnings look like the errors with the "while renaming ..." removed 
from the end.

The backtrace was:

Traceback (most recent call last):
  File "rdiffbackup\run.py", line 170, in <module>
  File "rdiffbackup\run.py", line 37, in main
  File "rdiffbackup\run.py", line 105, in main_run
  File "rdiffbackup\actions\backup.py", line 159, in run
  File "rdiff_backup\backup.py", line 39, in mirror_compat200
  File "rdiff_backup\backup.py", line 197, in patch
  File "rdiff_backup\rorpiter.py", line 146, in __call__
  File "rdiff_backup\backup.py", line 595, in fast_process_file
  File "rdiff_backup\longname.py", line 152, in get_mirror_inc_rps
  File "rdiff_backup\longname.py", line 135, in find_inc_pair
  File "rdiff_backup\longname.py", line 313, in _check_new_index
  File "rdiff_backup\longname.py", line 290, in wrap_call
  File "rdiff_backup\longname.py", line 306, in make_parent
  File "rdiff_backup\rpath.py", line 802, in makedirs
  File "os.py", line 225, in makedirs
FileNotFoundError: [WinError 3] The system cannot find the path specified: 
b'E:/Backup of Data Volume/rdiff-backup-data/increments/Saved files from XPS 
8500/pcanning 
AppData/Local/IsolatedStorage/lcurzgy2.mpt/d43wfibz.sxp/StrongName.p1ksvpr1tqyz1i0rntyvyoufratxuqjq/AssemFiles/oauth-tax.platform.intuit.com-prdatnreszapc4a29dbipmzhcuwStLHhvlDxrbPq-0'
[39876] Failed to execute script 'run' due to unhandled exception!

Any ideas for what might be causing these problems and how to resolve them?