I had the same issue, only thing I found to work was to play on my windows 7 installation instead.
You could try this to downgrade if you have the steam version: https://steamcommunity.com/sharedfiles/filedetails/?id=1086279994
I haven't tried it though so not sure if it works.
This is a discord server made for speedrunning the HPL engine games. Pretty much everyone that runs this game is in it.
15-Oct-18 Edit: Updated the load remover again to make it compatible with the hardmode update.
Today I updated the load remover that Fatalis made to work with the newest version of Amnesia available on steam.
You can get the new load remover by typing "Amnesia: The Dark Descent" in LiveSplit's Splits Editor and clicking Activate. You don't have to download anything manually. After that just right-click Livesplit and go to Compare Against -> Game Time and then you should be good to go.
It should work identical to the load remover Fatalis made since I only changed which memory addresses it writes to and reads from.
This updated version however does not work with previous versions of Amnesia.
If you for whatever reason want the old load remover back you can get it here: http://fatalis.pw/livesplit/update/Components/LiveSplit.Amnesia.dll Just replace LiveSplit.Amnesia.dll in your Livesplit/Components folder and it should work.
With the newest version you don't need to worry about the unpatch and alt tab fix links in the resources tab.
If you have any issues with the new load remover send me a pm on discord.
That's all, good luck speedrunning.