diff --git a/ack/4.17_cluster-density_ack.yaml b/ack/4.17_cluster-density_ack.yaml
new file mode 100644
index 0000000..ed97d53
--- /dev/null
+++ b/ack/4.17_cluster-density_ack.yaml
@@ -0,0 +1 @@
+---
diff --git a/ack/4.17_crd-scale_ack.yaml b/ack/4.17_crd-scale_ack.yaml
new file mode 100644
index 0000000..ed97d53
--- /dev/null
+++ b/ack/4.17_crd-scale_ack.yaml
@@ -0,0 +1 @@
+---
diff --git a/ack/4.17_node-density_ack.yaml b/ack/4.17_node-density_ack.yaml
new file mode 100644
index 0000000..ed97d53
--- /dev/null
+++ b/ack/4.17_node-density_ack.yaml
@@ -0,0 +1 @@
+---
diff --git a/ack/4.18_cluster-density_ack.yaml b/ack/4.18_cluster-density_ack.yaml
index ea2bb4d..2311e99 100644
--- a/ack/4.18_cluster-density_ack.yaml
+++ b/ack/4.18_cluster-density_ack.yaml
@@ -2,4 +2,13 @@
 ack: 
   - uuid: 7f7337aa-cee3-4a36-b154-a7c48ed1fb75
     metric: etcdCPU_avg
-    reason: "Below 10%"
\ No newline at end of file
+    reason: "Below 10%"
+  - uuid: 4eeee274-53ac-4e75-855f-139dc743606b
+    metric: kubelet_avg
+    reason: "Started thread with node team"
+  - uuid: 22e90f4e-1c79-4d9d-b2f6-b95a7072738c
+    metric: kubelet_avg
+    reason: "Tooling issue - kubeburner"
+  - uuid: 22e90f4e-1c79-4d9d-b2f6-b95a7072738c
+    metric: ovnCPU_avg
+    reason: "Tooling issue - kubeburner"
diff --git a/ack/4.19_crd-scale_ack .yaml b/ack/4.19_crd-scale_ack.yaml
similarity index 100%
rename from ack/4.19_crd-scale_ack .yaml
rename to ack/4.19_crd-scale_ack.yaml
diff --git a/pkg/algorithms/edivisive/edivisive.py b/pkg/algorithms/edivisive/edivisive.py
index 224858d..1afe47c 100644
--- a/pkg/algorithms/edivisive/edivisive.py
+++ b/pkg/algorithms/edivisive/edivisive.py
@@ -25,7 +25,8 @@ def _analyze(self):
         if len(self.options["ack"]) > 1 and self.options["ackMap"] is not None:
             for ack in self.options["ackMap"]["ack"]:
                 pos = series.find_by_attribute("uuid",ack["uuid"])
-                ackSet.add(str(pos[0]) + "_" + ack["metric"])
+                if len(pos) > 0 :
+                    ackSet.add(str(pos[0]) + "_" + ack["metric"])
 
         # filter by direction and ack'ed issues
         for metric, changepoint_list in change_points_by_metric.items():