I have tried upgrading to Teamviewer 12 Beta, though this is somewhat inconvenient, as my company has licensed Teamviewer 11 corporate and I cannot as yet upgrade my Teamviewer install, so I used Teamviewer Portable 12 on my client machine (though I fully upgraded to TV 12 Beta on the remote host). This did not solve the problem however, so Teamviewer 12 suffers from the same deficiency, i.e. no unattended connection to a remote before someone has logged in locally.