There is a bug with New Gear Girl Character. I can't tell if it's Common Prototypes or Metal Stars.

3.068 Error ModManager.cpp:1758: Error while loading entity prototype "character-corpse" (character-corpse): Invalid pictures index: 5, expected value in the range of 1 to 4. in property tree at ROOT.character-corpse.character-corpse
Modifications: Base mod › Space Age › ○🌐Metal and Stars › New Gear Girl Character 2.0

No worries, it seems most character mods are broken, wish I could help but the only thing I could recommend you is grabbing the files of that mod and trying to "shorten" the images until they work

I believe I found the issue, it might have to do something with the metal and stars mech armor prototype, from my understanding at this moment it's the issue that the mech armor is limited somewhere to only show on max of 4 death sprites and most modded characters have 5 which leaves the armor screaming and breaking the whole line of mods, at least that is my theory

The closest I have found was the "Prototype-mech-armor-animations.lua" which contains a local for mech corpse with a frame count of 2 but I am uncertain whether that is the root of the issue

Something of an eureka, removing the last 2 lines from that file fixed it for me