skyscraper custom system ( please set a platform ) help

[polobear31]

/opt/retropie/configs/all/emulationstation/es_systems.cfg

<system>
   <name>mortall</name>
   <fullname>mortal kombat</fullname>
   <path>/home/pi/RetroPie/roms/kombat</path>
   <extension>.7z .cue .fba .iso .zip .7Z .CUE .FBA .ISO .ZIP</extension>
   <command>/opt/retropie/supplementary/runcommand/runcommand.sh 0 _SYS_ mame-libretro %ROM%</command>
   <platform>arcade</platform>
   <theme>kombat</theme>
 </system>
<system>
   <name>fighting</name>
   <fullname>street fighter games</fullname>
   <path>/home/pi/RetroPie/roms/fighting</path>
   <extension>.7z .cue .fba .iso .zip .7Z .CUE .FBA .ISO .ZIP</extension>
   <command>/opt/retropie/supplementary/runcommand/runcommand.sh 0 _SYS_ mame-libretro %ROM%</command>
   <platform>arcade</platform>
   <theme>fighting</theme>
 </system>

the roms and the custom logo show up game works but now when i try and scrape it using skyscraper i get this message.
roms folder
/home/pi/RetroPie/roms/kombat

[mitu]

I think that's not supported at the moment, but I think it's a planned feature (custom platform aliases). I see you found a workaround in the mean time :).