There are 2 solutions. You wait until the weld-core-1.1.8.FINAL.jar will be updated! Or you get the source code and do a hard fix in org.jboss.weld.context.AbstractBoundContext:
public void deactivate() {
if (getBeanStore() != null )
{ getBeanStore().detach(); super.deactivate(); }
}
For more information see https://issues.jboss.org/browse/WELD-1020?_sscc=t