I used to be farming crimson hearts by crimson guardian. And I found shad's BS and assulter don't work, actually the stun doesn't work 90%. Any shadowers have this problem?
As a temporary fix, change your client's properties to run in compatibility mode for Windows 7: Find your MapleRoyals folder, should be C:\MapleRoyals\, right click MapleRoyals.exe and select properties. Select the Compatibility tab and tick 'Run this program in compatibility mode for:' and choose Windows 7. Click Apply and then launch the client.