[1.12.2] Forge Installer crashes on launch and error regarding to out of bounds exception occurs

[Zeff_T]

forge-1.12.2-14.23.5.2847-installer.jar.log

tried installing forge for a custom server for RLCRAFT modpack. Java and MC have been reinstalled several times , temp files cleaned , directories checked , jarfix applied and console launch/ powershell launch gives the same error logs as the ones attached. If anyone ever faced a similar problem , would love some thoughts on this . I think i missed some stuff out so appreciate any help : )

tried forge versions : forge-1.12.2-14.23.5.2838 through 2853

 

installer 2847(exe).log

[Luis_ST]

1.12 is no longer supported on this forum.
Please update to a modern version of Minecraft to receive support.

[Zeff_T]

allright i shall remove the post