I have the same issue and all I did was add the bonsi tree mod back in. All works fine with the 0.3.14 version and the world is back online and we are all able to log in. Just remember to let people know they will also need to install the bonsie tree mod into there own games mod folder. Hope this helps :)

Originally posted by @XPSuedoX in #692 (comment)

This is also another option if your worried about bonsie dupping - so do this instead of re adding bonsi trees mod if you prefer

Open your world folder with NBTExplorer, open level.dat > Data > WorldGenSettings > Dimensions , delete bonsaitree's entry and save

We had to hotfix to add the mod back in until forge is fixed.. Update and you should be fine.