I installed the proposed linux-image-4.4.0-40-generic, besides linux-headers-4.4.0-40-generic and linux-image-extra-4.4.0-40-generic, the latter needed for my laptop to work properly. I can confirm that the DFS mounting problem is solved for my system.
I installed the proposed linux-image- 4.4.0-40- generic, besides linux-headers- 4.4.0-40- generic and linux-image- extra-4. 4.0-40- generic, the latter needed for my laptop to work properly. I can confirm that the DFS mounting problem is solved for my system.