Backups not working file INDEX

I upgraded to Server 2 and after getting backups to ISCSI things worked ok for a few days.
Server can access ISCSI volume on NAS without issues.

SERVER Windows 2012r2 VM
Clients Windows 7

I check the logs on the server and clients
Very simple file backup settings:
c:\users*.*;

All clients from the server logs show errors similar to this:

Errors 08/05/16 06:10 Cannot access path to backup: “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy19\users*.*” Errorcode: 123 - The filename, directory name, or volume label syntax is incorrect.
Errors 08/05/16 06:10 Constructing of filelist of “XXXX-WELXXXX” failed: error - index error
Errors 08/05/16 06:10 Backup had an early error. Deleting partial backup

Snapshot of errors on a clients debug LOG

2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\Local Settings”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\My Documents”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\NetHood”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\PrintHood”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\Recent”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\SendTo”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\Start Menu”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\Users\sstanfill\Templates”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\ProgramData\Application Data”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\ProgramData\Desktop”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\ProgramData\Documents”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\ProgramData\Favorites”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\ProgramData\Start Menu”
2016-08-02 17:23:16: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy22\ProgramData\Templates”
2016-08-03 01:13:42: WARNING: Restarting shadow copy of C:\ because it was started by this server
2016-08-03 19:00:55: WARNING: Restarting shadow copy of C:\ because it was started by this server
2016-08-04 03:03:57: WARNING: Restarting shadow copy of C:\ because it was started by this server
2016-08-04 08:55:11: WARNING: Restarting shadow copy of C:\ because it was started by this server
2016-08-04 08:57:44: ERROR: Indexing files failed, because of error
2016-08-04 08:58:26: ERROR: Recvfrom error in CUDPThread::UdpStep
2016-08-04 08:58:26: ERROR: Last error: 10058
2016-08-04 09:41:11: ERROR: Recvfrom error in CUDPThread::UdpStep
2016-08-04 09:41:11: ERROR: Last error: 10058
2016-08-04 19:03:20: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy27\ProgramData\Application Data”
2016-08-04 19:03:20: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy27\ProgramData\Desktop”
2016-08-04 19:03:20: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy27\ProgramData\Documents”
2016-08-04 19:03:20: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy27\ProgramData\Favorites”
2016-08-04 19:03:20: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy27\ProgramData\Start Menu”
2016-08-04 19:03:20: ERROR: Error getting SID of ACE entry of file “\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy27\ProgramData\Templates”
2016-08-05 03:03:36: WARNING: Restarting shadow copy of C:\ because it was started by this server

I remember changing backup path a few days ago from c:\users to ------> c:\users*.*
It seems that some clients fail with indexing issues with this new setting.

I changed it back to c:\users; and restarted server service and incremental is working on a couple of clients now.

Just curious, why did you use C:\Users*.*? Isn’t that implied? Or are these files named users1, users2 etc?