Same issue here. Windows 8.1 Pro and the share is in Windows 7 Pro. I have shared the entire drive on the remote system and gave Everyone Full Control. I am able to create folders, files, move them, delete them, etc. with Windows Explorer. Turned both clients firewalls off, but VEEAM keeps throwing the same Error: Access is denied, failed to create or open file.
Would logs help? Which ones do you need?