I played in modpack in which were Better With Mods and Forestry. When I built forestry multiblock farm to automate wood producing I got a problem, that I cannot able to get wooden logs. The output was: http://prntscr.com/q4rgqw.

So, I suppose i can explain how it works: Forestry farm works in that way, like if u harvest tree with your hand without axe and when it happens you get oak bark and sawdust and the reason is better with mods... Unfortunately, we cant put any axe in forestry farm, so it's impossible to fix it without... idk.. recoding maybe..

you can set it so you get the logs again, you do not get bark when punching then though, i wish we could set it so you get both. Or set the forestry so it uses axe or something.
You can find the setting in : betterwithmods.cfg -> B:HCLumber=false