Ah yes these don't work on macs, mainly because it is meant for a windows direct 3D mode. Though, it could also be a problem on how you downloaded it, make sure you download it right! Also, maybe try redownloading feralheart and trying again, sometimes Feralheart on macs is a bit derpy. If that doesn't work do not try again, take all the files out that you downloaded, and just keep playing Feralheart. Yes, this is an inconvenience, so sorry dear c:
Something you may want to check, is your wineskin, if you downloaded an upgrade in the past, this could be the problem. You can also ask the creator to convert their night and day mod so that macs may use it as well.
I will try this download myself, to make sure It doesn't work on macs, may i have the link?