when publishing to maven repository central missing signature on everything

I got the publishing to work but when closing the staged release I get

-Missing Signature: '/org/apache/kafka/kafka_2.9.2/0.8.0-beta1/kafka_2.9.2-0.8.0-beta1.jar.asc' does not exist for 'kafka_2.9.2-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/kafka_2.9.2/0.8.0-beta1/kafka_2.9.2-0.8.0-beta1-javadoc.jar.asc' does not exist for 'kafka_2.9.2-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.2/0.8.0-beta1/contrib_2.8.2-0.8.0-beta1.pom.asc' does not exist for 'contrib_2.8.2-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.2/0.8.0-beta1/contrib_2.8.2-0.8.0-beta1.jar.asc' does not exist for 'contrib_2.8.2-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.2/0.8.0-beta1/contrib_2.8.2-0.8.0-beta1-sources.jar.asc' does not exist for 'contrib_2.8.2-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.2/0.8.0-beta1/contrib_2.8.2-0.8.0-beta1-javadoc.jar.asc' does not exist for 'contrib_2.8.2-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.2/0.8.0-beta1/kafka-perf_2.8.2-0.8.0-beta1-javadoc.jar.asc' does not exist for 'kafka-perf_2.8.2-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.2/0.8.0-beta1/kafka-perf_2.8.2-0.8.0-beta1.jar.asc' does not exist for 'kafka-perf_2.8.2-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.2/0.8.0-beta1/kafka-perf_2.8.2-0.8.0-beta1.pom.asc' does not exist for 'kafka-perf_2.8.2-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.2/0.8.0-beta1/kafka-perf_2.8.2-0.8.0-beta1-sources.jar.asc' does not exist for 'kafka-perf_2.8.2-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.0/0.8.0-beta1/contrib_2.8.0-0.8.0-beta1-javadoc.jar.asc' does not exist for 'contrib_2.8.0-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.0/0.8.0-beta1/contrib_2.8.0-0.8.0-beta1.jar.asc' does not exist for 'contrib_2.8.0-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.0/0.8.0-beta1/contrib_2.8.0-0.8.0-beta1-sources.jar.asc' does not exist for 'contrib_2.8.0-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.8.0/0.8.0-beta1/contrib_2.8.0-0.8.0-beta1.pom.asc' does not exist for 'contrib_2.8.0-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/kafka_2.8.2/0.8.0-beta1/kafka_2.8.2-0.8.0-beta1-sources.jar.asc' does not exist for 'kafka_2.8.2-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/kafka_2.8.2/0.8.0-beta1/kafka_2.8.2-0.8.0-beta1-javadoc.jar.asc' does not exist for 'kafka_2.8.2-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/kafka_2.8.2/0.8.0-beta1/kafka_2.8.2-0.8.0-beta1.pom.asc' does not exist for 'kafka_2.8.2-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/kafka_2.8.2/0.8.0-beta1/kafka_2.8.2-0.8.0-beta1.jar.asc' does not exist for 'kafka_2.8.2-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.0/0.8.0-beta1/kafka-perf_2.8.0-0.8.0-beta1-javadoc.jar.asc' does not exist for 'kafka-perf_2.8.0-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.0/0.8.0-beta1/kafka-perf_2.8.0-0.8.0-beta1.pom.asc' does not exist for 'kafka-perf_2.8.0-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.0/0.8.0-beta1/kafka-perf_2.8.0-0.8.0-beta1-sources.jar.asc' does not exist for 'kafka-perf_2.8.0-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.8.0/0.8.0-beta1/kafka-perf_2.8.0-0.8.0-beta1.jar.asc' does not exist for 'kafka-perf_2.8.0-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.1/0.8.0-beta1/contrib_2.9.1-0.8.0-beta1.pom.asc' does not exist for 'contrib_2.9.1-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.1/0.8.0-beta1/contrib_2.9.1-0.8.0-beta1-sources.jar.asc' does not exist for 'contrib_2.9.1-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.1/0.8.0-beta1/contrib_2.9.1-0.8.0-beta1-javadoc.jar.asc' does not exist for 'contrib_2.9.1-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.1/0.8.0-beta1/contrib_2.9.1-0.8.0-beta1.jar.asc' does not exist for 'contrib_2.9.1-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.9.1/0.8.0-beta1/kafka-perf_2.9.1-0.8.0-beta1.pom.asc' does not exist for 'kafka-perf_2.9.1-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.9.1/0.8.0-beta1/kafka-perf_2.9.1-0.8.0-beta1.jar.asc' does not exist for 'kafka-perf_2.9.1-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.9.1/0.8.0-beta1/kafka-perf_2.9.1-0.8.0-beta1-sources.jar.asc' does not exist for 'kafka-perf_2.9.1-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/kafka-perf_2.9.1/0.8.0-beta1/kafka-perf_2.9.1-0.8.0-beta1-javadoc.jar.asc' does not exist for 'kafka-perf_2.9.1-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/kafka_2.9.1/0.8.0-beta1/kafka_2.9.1-0.8.0-beta1-javadoc.jar.asc' does not exist for 'kafka_2.9.1-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/kafka_2.9.1/0.8.0-beta1/kafka_2.9.1-0.8.0-beta1.pom.asc' does not exist for 'kafka_2.9.1-0.8.0-beta1.pom'.
-Missing Signature: '/org/apache/kafka/kafka_2.9.1/0.8.0-beta1/kafka_2.9.1-0.8.0-beta1-sources.jar.asc' does not exist for 'kafka_2.9.1-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/kafka_2.9.1/0.8.0-beta1/kafka_2.9.1-0.8.0-beta1.jar.asc' does not exist for 'kafka_2.9.1-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.2/0.8.0-beta1/contrib_2.9.2-0.8.0-beta1-sources.jar.asc' does not exist for 'contrib_2.9.2-0.8.0-beta1-sources.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.2/0.8.0-beta1/contrib_2.9.2-0.8.0-beta1-javadoc.jar.asc' does not exist for 'contrib_2.9.2-0.8.0-beta1-javadoc.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.2/0.8.0-beta1/contrib_2.9.2-0.8.0-beta1.jar.asc' does not exist for 'contrib_2.9.2-0.8.0-beta1.jar'.
-Missing Signature: '/org/apache/kafka/contrib_2.9.2/0.8.0-beta1/contrib_2.9.2-0.8.0-beta1.pom.asc' does not exist for 'contrib_2.9.2-0.8.0-beta1.pom'.

OK

looking at http://www.scala-sbt.org/0.12.3/docs/Community/Using-Sonatype.html we need the sbt signing plugin like

This file specifies the plugins for your project. If you intend to sign the artefacts, you'll need to include @jsuereth's xsbt-gpg-plugin:

resolvers += Resolver.url("sbt-plugin-releases", /* no new line */
new URL("http://scalasbt.artifactoryonline.com/scalasbt/sbt-plugin-releases")) /* no new line */
(Resolver.ivyStylePatterns)

addSbtPlugin("com.jsuereth" % "xsbt-gpg-plugin" % "0.5")