The Windows version does not work on anything but Windows. The All version will work on all platforms, but you'll be unable to use the update functions as those require access to the filesystem and need a DLL. ;)
To make it work on Windows I had to gms_network() to the networking event, as said in the getting started. With this both Windows and iOS connect and get matched against each other, but the iOS crashes with Illegal Buffer Index at gml_Script_XServer_readinstance. I found this error athttp://gamemakerserver.com/en/news/14/, but I am using 1.3.1354 and on Windows it works fine.
Was going to post something about how I'm not able to test the extension on iOS devices, but it seems like this is actually a bug. It'll be fixed in time to go into the 1.8 update which I'm hoping to release very soon (preferrably before christmas if at all possible :P).
Not sure why the windows version is not crashing, it should too. Whatever the case, thank you for bringing this to my attention!
It seems to crash on Windows as well, the iOS version is slower, so it got the data that causes the crash earlier. gms_instance_sync(ins, is_onetime); causes the crash,
while gms_instance_sync(ins_stats, is_full ); doesn't, but is not working.
gms_self_set("myname",playername); seems to work fine.
If you need this fixed before I am able to put out an update, right-click the extension, select "Open Extension Directory". Open the GameMaker Server .gml file, and search for a line that starts with "#define wle_step" (without quotes). Right below that line, add a line that says "string(argument1);" (without quotes). Save & close the file. That should fix it :)