Intellij Idea - "gradle project sync failed" in Android project

Press "Refresh all Gradle projects" in View > Tool Windows > Gradle

CKEditor + Symfony - Cannot read property 'icons'

Be sure in config.yml in "extraPlugins" plugin name is the same as in specified plugin's file plugin.js first row, for example: "CKEDITOR.plugins.add( 'filepreview', {", where 'filepreview' is config.yml's plugin name.

Sonata-Media PublicDownloadStrategy not working in Prod environment

After changing config.yml file, do not forget to clear prod cache (app/console cache:clear -e prod)

[visual studio] installer 'install'/'uninstall' not available

Try to "build"/"Rebuild" installer project in solution.

symfony 404 not found on file upload

be sure you changed "upload_max_size" in needed php.ini, added "client_max_body_size 100m;" in case nginx.conf, and do not forget to restart all php, nginx, apache2 daemons, or better reboot system.

twig unrecognized field 0

because you forget add parameter as associated array, for example

findOneBy(['providerReference' => $reference])

, not (['provideReference', $reference])

[Symfony] [ckeditor] browse / upload buttons missing - how to fix

be sure you don't have duplicate call of ivory_ck_editor in config.yml file.