ahahahahahahahahahahahahaha
macs are so fun.
okay, first off, that bottom error looks serious, you should probably fix it.
second: you packaged your add-on like this:
add-on.zip/add-on/server.cs
this is bad ^
add-on.zip/server.cs
this is good ^
third thing, try looking up 7zip and see if there's a mac version.