Policy not found: null (after import)

{
    "responseCode": 500,
    "message": "Policy not found: null",
    "trace": "io.apiman.gateway.engine.beans.exceptions.PolicyNotFoundException: Policy not found: null
	at io.apiman.gateway.engine.policy.PolicyFactoryImpl.loadPolicy(PolicyFactoryImpl.java:82)
	at io.apiman.gateway.engine.impl.ServiceRequestExecutorImpl.loadPolicies(ServiceRequestExecutorImpl.java:366)
	at io.apiman.gateway.engine.impl.ServiceRequestExecutorImpl.access$1400(ServiceRequestExecutorImpl.java:77)
	at io.apiman.gateway.engine.impl.ServiceRequestExecutorImpl$4.handle(ServiceRequestExecutorImpl.java:306)
	at io.apiman.gateway.engine.impl.ServiceRequestExecutorImpl$4.handle(ServiceRequestExecutorImpl.java:282)
	at io.apiman.gateway.engine.impl.SecureRegistryWrapper$2.handle(SecureRegistryWrapper.java:125)
	at io.apiman.gateway.engine.impl.SecureRegistryWrapper$2.handle(SecureRegistryWrapper.java:117)
	at io.apiman.gateway.engine.es.CachingESRegistry.getContract(CachingESRegistry.java:171)
	at io.apiman.gateway.engine.impl.SecureRegistryWrapper.getContract(SecureRegistryWrapper.java:117)
	at io.apiman.gateway.engine.impl.ServiceRequestExecutorImpl.execute(ServiceRequestExecutorImpl.java:282)
	at io.apiman.gateway.platforms.servlet.GatewayServlet.doAction(GatewayServlet.java:235)
	at io.apiman.gateway.platforms.servlet.GatewayServlet.doGet(GatewayServlet.java:81)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
	at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:61)
	at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
	at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
	at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:56)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45)
	at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:63)
	at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58)
	at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70)
	at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:261)
	at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:247)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:76)
	at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:166)
	at io.undertow.server.Connectors.executeRootHandler(Connectors.java:197)
	at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:759)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
"