Linux users, this happened to me running the Laigter appimage so FYI:
If you attempt to add any of the Laigter .so-file plugins from this page, and it crashes Laigter, and then continues to crash on app startup, you will need to remove the .so plugin files auto-copied to your home directory to allow Laigter to start normally.
You will find the .so plugin files at:
/home/[you]/.local/share/laigter/plugins
Go ahead and delete whichever last plugin you activated which caused the crash. You should now be able to run Laigter again.
For me, all three linux plugins from this itch-io page crashed Laigter. However, the .so files for the three plugins found on their github pages installed and worked fine with no crashes:
https://github.com/azagaya/LaigterNormalBrushPlugin/releases/download/continuous...
https://github.com/azagaya/LaigterTextureBrushPlugin/releases/download/continuou...
https://github.com/azagaya/LaigterHSPOBrush/releases/download/continuous/libhspo...
so it looks like the issue lies with the itch.io download versions.