During installation of the plugin, I got this error:
Error: Cannot find module '/usr/src/app/node_modules/nodebb-plugin-share-post-icons/library.js'. Please verify that the package.json has a valid "main" entry
Indeed, when I check the package.json file, I see this configuration:"main": "library.js"
And indeed, such file does not exists...
The strangest thing is that I successfully installed the plugin on another NodeBB instance and it is working perfectly.