Known issues

Disable Gin's dialog styles in Frontend theme

Gin is designed to provide a seamless content editor experience and does expose the admin styles in the Frontend (8.x-3.x). If you use your own dialog styling you can disable the Gin styles being exposed in the frontend with:

libraries-override:
  claro/claro.drupal.dialog: false
  gin/dialog: false
  gin/gin_dialog: false

Can't install Gin because of Composer's minimum stability requirement

You can work around this issue with using the following install command:

composer require drupal/gin_toolbar:^1.0@rc drupal/gin:^3.0@rc

See also Install via composer

Gin's icons don't render correctly with AdvAgg enabled

This might be a problem regarding AdvAgg's outdated JS & CSS compressors. Switching the CSS compressor to anything else than YUI (last release 5 years ago, abandoned by the developers) and the JS processor to anything other than JSqueeze (last release 8 years ago, abandoned by the developers) should fix the issue.

Gin does not support being applied via a theme negotiator

If you are going to use Gin as your admin theme, it must be set in configuration. If you configure your admin theme to be something else but apply Gin via a theme negotiator, Gin will not render properly. This is by design; Gin is only supported when configured to be the default theme.