您正在尝试使用非常老的Firebase客户端库.最新版本列在发行说明中.您应该确保同时使用所有最新版本.

You're trying to use use very old Firebase client libraries. The latest versions are listed in the release notes. You should make sure to use all the most recent versions together.

implementation 'com.google.firebase:firebase-database:19.2.1'
implementation 'com.google.firebase:firebase-auth:19.2.0'
implementation 'com.google.firebase:firebase-messaging:20.1.0'

您也不应再使用firebase-core.如果您尝试使用Google Analytics(分析)，请执行以下操作:

You should also no longer use firebase-core. If you are trying to use Analytics, do this instead:

implementation 'com.google.firebase:firebase-analytics:17.2.2'