The most common error is that; realms, vaults and other areas in RotMG appear as a fully blacked out screen.
Here is how to fix this error and allow the hacks to work
All you need to do is turn off 'Hardware Acceleration' in your RotMG options
Use either the hotkey 'O' or press the spanner icon, when in Nexus, to access RotMG options
Move to the 'Graphics' tab at the top..
..and ensure 'Hardware Acceleration' is 'Off' then press continue
Changing this setting requires a client re-start for the changes to take effect!