Hey David,
Several of my custom presets cause G’MIC GIMP plugin to crash and it won’t open again until either I edit my preset file with that preset out or close and re-open GIMP. Engrave and Cartoon are among my custom presets that crash. When I went to the default engrave preset it appeared to work fine so not sure what is caused G’MIC plugin to crash. Going back to the alpha pre-release for now. 