Error importing content pack, please ensure it is a valid JSON file. Check your Graylog logs for more information. Null id at [Source: org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream@6f86cb17; line: 278, column: 1] (through reference chain: org.graylog2.contentpacks.model.AutoValue_LegacyContentPack$Builder[“id”])
Seems that there may have been an issue with copy/pasting the file. Or there’s an error in there. Based on that one error text I would think there’s a syntax error, where a bracket or (double) quote is not properly close.