Urgent question - failed plugin and now getting internal server error Hope someone can help asap - we tried to install a plugin through craftcms 3 (Cache Flag) and now getting 'The configuration for the "gc" component must contain a "class" element.' 

Does anyone know how to resolve this?
This seems unrelated to the Cache Flag plugin, and more likely due to some bad code in config/app.php (or app.web.php).

If you have either of those files, check what changes you’ve made to it/them recently.