I've just installed the material theme editor from https://material.io/tools/theme-editor/ but when I click on Material > "Open theme editor" from my Sketch plugins tab, nothing opens. I know the plugin successfully installed because I can click on Material > "Upload to Gallery" and a window pops up, but nothing for opening the theme editor. The theme editor website says you need macOS High Sierra (10.13) or later, which I do have, so this can't be the issue.
Is anyone else having this issue or know how to resolve it? Thanks!