I can't seem to get cert-manager working:

$ kubectl get certificates -o wide
NAME              READY   SECRET            ISSUER             STATUS                                                                    AGE
example-ingress   False   example-ingress   letsencrypt-prod   Waiting for CertificateRequest "example-ingress-2556707613" to complete   6m23s
$ kubectl get CertificateRequest -o wide
NAME                         READY   ISSUER             STATUS                                                                               AGE
example-ingress-2556707613   False   letsencrypt-prod   Referenced "Issuer" not found: issuer.cert-manager.io "letsencrypt-prod" not found   7m7s

and in the logs i see:

I1025 06:22:00.117292       1 sync.go:163] cert-manager/controller/ingress-shim "level"=0 "msg"="certificate already exists for ingress resource, ensuring it is up to date" "related_resource_kind"="Certificate" "related_resource_name"="example-ingress" "related_resource_namespace"="default" "resource_kind"="Ingress" "resource_name"="example-ingress" "resource_namespace"="default"
I1025 06:22:00.117341       1 sync.go:176] cert-manager/controller/ingress-shim "level"=0 "msg"="certificate resource is already up to date for ingress" "related_resource_kind"="Certificate" "related_resource_name"="example-ingress" "related_resource_namespace"="default" "resource_kind"="Ingress" "resource_name"="example-ingress" "resource_namespace"="default"
I1025 06:22:00.117382       1 controller.go:135] cert-manager/controller/ingress-shim "level"=0 "msg"="finished processing work item" "key"="default/example-ingress"
I1025 06:22:00.118026       1 sync.go:361] cert-manager/controller/certificates "level"=0 "msg"="no existing CertificateRequest resource exists, creating new request..." "related_resource_kind"="Secret" "related_resource_name"="example-ingress" "related_resource_namespace"="default" "resource_kind"="Certificate" "resource_name"="example-ingress" "resource_namespace"="default"
I1025 06:22:00.147147       1 controller.go:129] cert-manager/controller/certificaterequests-issuer-venafi "level"=0 "msg"="syncing item" "key"="default/example-ingress-2556707613"
I1025 06:22:00.147267       1 sync.go:373] cert-manager/controller/certificates "level"=0 "msg"="created certificate request" "related_resource_kind"="Secret" "related_resource_name"="example-ingress" "related_resource_namespace"="default" "resource_kind"="Certificate" "resource_name"="example-ingress" "resource_namespace"="default" "request_name"="example-ingress-2556707613"
I1025 06:22:00.147284       1 controller.go:129] cert-manager/controller/certificaterequests-issuer-acme "level"=0 "msg"="syncing item" "key"="default/example-ingress-2556707613"
I1025 06:22:00.147273       1 conditions.go:200] Setting lastTransitionTime for CertificateRequest "example-ingress-2556707613" condition "Ready" to 2019-10-25 06:22:00.147254385 +0000 UTC m=+603.871617341
I1025 06:22:00.147392       1 conditions.go:200] Setting lastTransitionTime for CertificateRequest "example-ingress-2556707613" condition "Ready" to 2019-10-25 06:22:00.147380513 +0000 UTC m=+603.871743521
E1025 06:22:00.147560       1 pki.go:128] cert-manager/controller/certificates "msg"="error decoding x509 certificate" "error"="error decoding cert PEM block" "related_resource_kind"="Secret" "related_resource_name"="example-ingress" "related_resource_namespace"="default" "resource_kind"="Certificate" "resource_name"="example-ingress" "resource_namespace"="default" "secret_key"="tls.crt"
I1025 06:22:00.147620       1 conditions.go:155] Setting lastTransitionTime for Certificate "example-ingress" condition "Ready" to 2019-10-25 06:22:00.147613112 +0000 UTC m=+603.871976083
I1025 06:22:00.147731       1 controller.go:129] cert-manager/controller/certificaterequests-issuer-ca "level"=0 "msg"="syncing item" "key"="default/example-ingress-2556707613"
I1025 06:22:00.147765       1 conditions.go:200] Setting lastTransitionTime for CertificateRequest "example-ingress-2556707613" condition "Ready" to 2019-10-25 06:22:00.14776244 +0000 UTC m=+603.872125380
I1025 06:22:00.147912       1 controller.go:129] cert-manager/controller/certificaterequests-issuer-selfsigned "level"=0 "msg"="syncing item" "key"="default/example-ingress-2556707613"
I1025 06:22:00.147942       1 conditions.go:200] Setting lastTransitionTime for CertificateRequest "example-ingress-2556707613" condition "Ready" to 2019-10-25 06:22:00.147938966 +0000 UTC m=+603.872301909
I1025 06:22:00.147968       1 controller.go:129] cert-manager/controller/certificaterequests-issuer-vault "level"=0 "msg"="syncing item" "key"="default/example-ingress-2556707613"
I1025 06:22:00.148023       1 conditions.go:200] Setting lastTransitionTime for CertificateRequest "example-ingress-2556707613" condition "Ready" to 2019-10-25 06:22:00.148017945 +0000 UTC m=+603.872380906

i deployed cert-manager via the manifest:

https://github.com/jetstack/cert-manager/releases/download/v0.11.0/cert-manager.yaml

$ kubectl get clusterissuer letsencrypt-prod -o yaml
apiVersion: cert-manager.io/v1alpha2
kind: ClusterIssuer
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"cert-manager.io/v1alpha2","kind":"ClusterIssuer","metadata":{"annotations":{},"name":"letsencrypt-prod"},"spec":{"acme":{"email":"me@me.com","privateKeySecretRef":{"name":"letsencrypt-prod"},"server":"https://acme-staging-v02.api.letsencrypt.org/directory","solvers":[{"http01":{"ingress":{"class":"nginx"}},"selector":{}}]}}}
  creationTimestamp: "2019-10-25T06:27:06Z"
  generation: 1
  name: letsencrypt-prod
  resourceVersion: "1759784"
  selfLink: /apis/cert-manager.io/v1alpha2/clusterissuers/letsencrypt-prod
  uid: 05831417-b359-42de-8298-60da553575f2
spec:
  acme:
    email: me@me.com
    privateKeySecretRef:
      name: letsencrypt-prod
    server: https://acme-staging-v02.api.letsencrypt.org/directory
    solvers:
    - http01:
        ingress:
          class: nginx
      selector: {}
status:
  acme:
    lastRegisteredEmail: me@me.com
    uri: https://acme-staging-v02.api.letsencrypt.org/acme/acct/11410425
  conditions:
  - lastTransitionTime: "2019-10-25T06:27:07Z"
    message: The ACME account was registered with the ACME server
    reason: ACMEAccountRegistered
    status: "True"
    type: Ready

and my ingress is:

$ kubectl get ingress example-ingress -o yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    cert-manager.io/issuer: letsencrypt-prod
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{"cert-manager.io/issuer":"letsencrypt-prod","kubernetes.io/ingress.class":"nginx","kubernetes.io/tls-acme":"true"},"name":"example-ingress","namespace":"default"},"spec":{"rules":[{"host":"example-ingress.example.com","http":{"paths":[{"backend":{"serviceName":"apple-service","servicePort":5678},"path":"/apple"},{"backend":{"serviceName":"banana-service","servicePort":5678},"path":"/banana"}]}}],"tls":[{"hosts":["example-ingress.example.com"],"secretName":"example-ingress"}]}}
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
  creationTimestamp: "2019-10-25T06:22:00Z"
  generation: 1
  name: example-ingress
  namespace: default
  resourceVersion: "1758822"
  selfLink: /apis/extensions/v1beta1/namespaces/default/ingresses/example-ingress
  uid: 921b2e91-9101-4c3c-a0d8-3f871dafdd30
spec:
  rules:
  - host: example-ingress.example.com
    http:
      paths:
      - backend:
          serviceName: apple-service
          servicePort: 5678
        path: /apple
      - backend:
          serviceName: banana-service
          servicePort: 5678
        path: /banana
  tls:
  - hosts:
    - example-ingress.example.com
    secretName: example-ingress
status:
  loadBalancer:
    ingress:
    - ip: x.y.z.a

any idea whats wrong? cheers,