Hi there!
When we made the DarkScape site we were pretty up against the wall as far as time goes.
As a result we didn't build in the functionality for the site to differentiate between Mac's and PC's.
As /u/MiniMau mentioned if anyone wants to play DarkScape on their Mac they can visit RuneScape Ways To Play and download the Mac client there before returning to DarkScape and continuing on.
Potentially it's something we'll look to include in the future, but much like the game the website depends on players interaction with the game and if we see a demand.
Thanks for bringing it up though, hopefully this will help some others avoid confusion!
Edit ~ WooHoo - First Reddit comment created successfully!
Okay, I went ahead and re-uploaded it to a new filehost.
http://www.filedropper.com/runescapemultilauncher
all you do is just download it and double click. there will be a pop-up asking which game mode you want to play. I will update it for the 4th game mode deadman on its release.
I do apologize. I just found the first free file host that didn't require registration.
https://www.runescape.com/ways-to-play
bottom of the page, second dot :) i do not officially support chromebooks (as i do not personally own one) so it will have to be trial and error to get it to run as i have gotten mixed feedback on chromebook compatibility.
however the install instructions should be the same. just follow the steps for installing through the archive or PPA
run the rsu-query.exe directly (easiest would be to make a bat file and make it write the output to a file)
and show me the output from the command prompt
batfile content:
@echo off "%CD%\rsu-query.exe" > "%CD%\rsu-debug.txt"
post the output on something like pastebin and link it here and i will take a look at it tomorrow for the time beeing you can make a shortcut to the runescape.exe with these parameters in the target line
C:\path\to\rsu\runescape.exe jagex-jav://www.runescape.com/jav_config_beta.ws
it will quite literally FORCE the rsu to load said jav_config and use whatever your current prm file for runescape is