Fail to import Content Packs from ver Graylog 2.4.3 to Graylog 4.2.1

Hello && Welcome

If this is not a default content pack then it would mean what ever content pack you have installed on GL version 2.4.3 no longer works for the newer version of Graylog.

If this is a default content pack you have to remove it and update/install your content pack.

To help you further please take a look here