Did quite a bit of research on this. Updated network settings, searching through numerous Log files, Event Viewer, registry settings, running DISM and sfc commands, installing a completely separate Veeam Backup server; you get the idea.
The solution to my problems was to run the backup job locally (Veeam Workstation) to get additional information.
As you can see, it is first erroring out at \\?\Volume…(disk 6).
I opened diskmgmt.msc . I have a dual boot system with Windows 7 I use occasionally for offline music production (because of compatibility issues). The disk 6, 2.4 GB was a System Recovery Drive for the Windows 7 OS, let’s call this drive J:\ . Keep in mind that I am only attempting to back up my live Windows 10 OS’s C:\ drive (specifically C:\ drive, and not the option “Operating System”). Somehow Veeam was attempting to backup the J:\ System Recovery Drive and erroring out because of it.
I deleted the System Restore partition with diskpart and ran the backup job locally with the Veeam Workstation client. Success! Backup ran without issue! I reverted my changes in Veeam to use the backup server instead, and the backup there was also successful. Since I was able to backup the C:\ drive successfully, lastly I chose the “Operating System” option, and again was successful.