OTG does this thing where it puts its Coremod component in a mods/1.12.2 folder and the coremod uses code from the main mod, so when the main mod is removed but not the coremod you get crashes like this.
Oh... dark theme made that hard to see.
Anyway you should not rely on a mod to bring up the log for you, my signature has info on the location of logs, please read it.
More or less.
Honestly a complain about this isn't going to take seriously by the dev team unless some proof is show from proper dedicated tools instead of Minecraft's debug screen.
You may have Java 8 installed but it's now what your Computer is choosing to use, try using the full path to the Java 8 binary instead of just invoking 'java'