Avamar: Backup fails with "error in source or target list". Activity monitor reports error code 10012

When an Avamar client is issued with a workorder, the backup fails immediately with "Backup Operation failed!". The reason is "error in source or target list".

The Avamar Administrator activity monitor reports the backups status as Failed Error with code 10012.

The client avagent log reports the following warning messages:

avagent Warning <6690>: CTL workorder "Default Schedule-Group-1380092400278" non-zero exit status 'code 536870924: error in source or target list'

The client avtar log provides more detailed information:
 

avtar Info <9914>: Expanding exclude=*.avi
avtar Info <9915>: Not expanding exclude=*.avi, wildcard must signify full directory or file name
avtar Info <9914>: Expanding exclude=*.mp3
avtar Info <9915>: Not expanding exclude=*.mp3, wildcard must signify full directory or file name
avtar Info <9914>: Expanding exclude=*.MP4
avtar Info <9915>: Not expanding exclude=*.MP4, wildcard must signify full directory or file name
avtar Info <9914>: Expanding exclude=*.avi
avtar Info <9915>: Not expanding exclude=*.avi, wildcard must signify full directory or file name
avtar Info <9914>: Expanding exclude=*.mp3
avtar Info <9915>: Not expanding exclude=*.mp3, wildcard must signify full directory or file name
avtar Info <9914>: Expanding exclude=*.MP4
avtar Info <9915>: Not expanding exclude=*.MP4, wildcard must signify full directory or file name
avtar Error <0000>: Specified source path ".\exclude=*.avi" does not exist; ignored
avtar Error <0000>: Specified source path ".\exclude=*.mp3" does not exist; ignored
avtar Error <0000>: Specified source path ".\exclude=*.MP4" does not exist; ignored
avtar Error <0000>: Specified source path ".\exclude=*.avi" does not exist; ignored
avtar Error <0000>: Specified source path ".\exclude=*.mp3" does not exist; ignored
avtar Error <0000>: Specified source path ".\exclude=*.MP4" does not exist; ignored
avtar Error <8012>: Error in path list: All paths are invalid..  Correct path list before retrying.
avtar Error <8939>: Errors occurred preparing for backup (exitcode=536870924).   No backup will be created.
avtar Info <6149>: Error summary: 8 errors: 8012, 8939, 0(6)
avtar Info <5314>: Command failed (8 errors, 6 warnings, exit code 10012: error in source or target list)

or

avtar Error <7553>: Specified source path ".\debug" does not exist; ignored
avtar Error <8012>: Error in path list: Path arguments must all be absolute or all relative (as indicated by first argument), but not both. Argument 'C:/' does not match style of first argument..  Correct path list before retrying.
avtar Error <8939>: Errors occurred preparing for backup (exitcode=536870924).   No backup will be created.
avtar Info <6149>: Error summary: 3 errors: 8012, 8939, 7553
avtar Info <5314>: Command failed (3 errors, exit code 10012: error in source or target list)

The initial error number can be either <0000> or <7553> depending on the version of Avamar. The path specified in the quotes can be anything, the key being that it starts with ".\

The user has tried adding a flag directly to the client by using the file C:\Program Files\avs\var\avtar.cmd. 
 
In the first example:
exclude=*.avi
exclude=*.mp3
exclude=*.MP4
 
In the second example:
debug

These flags are incorrectly formatted. They cause avtar to believe that they are source data files or directories. Avtar tries to scan for them as paths on the client. 

Since the path ".\exclude=*.MP4" or ".\debug" does not exist on the client, avtar considers the source dataset to be invalid.

When using flags in the .cmd files in the Avamar client directory (that is to say, in avtar.cmd or avagent.cmd), flags must be prefixed with two hyphens. 
 
For example;
 --exclude=*.avi
--debug
--verbose

Paths to be backed up can also be added to the avtar.cmd file, but they must be valid paths.

And example of an avtar.cmd file with both flags and paths would be:
C:\Users
--exclude=*.mp3