I tried to install MixinCompat but that doesn't worked either.

1.7.10 doesn't have mixin module. So as @LinuxSquare suggests, I need more info to reproduce the issue.
Since my last test 1.7.10 doesn't seems to crash.

Howdy @Dragongameryeet

It's a pity that it doesn't work.

But it would be useful, if you could post some more information such as:

• The active mods you've installed alongside MorePlanets, Galacticraft & MixinCompat (including the release-tag of each mod)
  • e.g.
  • GalacticraftCore-1.7-3.0.12.504
  • Galacticraft-Planets-1.7-3.0.12.504
  • MicdoodleCore-1.7-3.0.12.504
  • More-Planets-1.7.10-1.4.4-GC502
  • etc.
• The Crash log as a paste.ubuntu.com / paste.gg link or as a code-tag inside here.
  • Windows:
    • If it's technic: %appdata%\.technic\modpacks\<name-of-modpack>\logs\latest.log
    • If it's Minecraft: %appdata%\.minecraft\logs\latest.log
  • Linux:
    • If it's technic: ~/.technic/modpacks/<name-of-modpack>/logs/latest.log
    • If it's Minecraft: ~/.minecraft/logs/latest.log

So he can best evaluate if it's MorePlanets or another mod causing your issue.