diff --git a/src/common/cluster-store_test.ts b/src/common/cluster-store_test.ts
new file mode 100644
index 0000000000..3fc3e0b60e
--- /dev/null
+++ b/src/common/cluster-store_test.ts
@@ -0,0 +1,333 @@
+import fs from "fs";
+import mockFs from "mock-fs";
+import yaml from "js-yaml";
+import { Cluster } from "../main/cluster";
+import { ClusterStore } from "./cluster-store";
+import { workspaceStore } from "./workspace-store";
+import { saveConfigToAppFiles } from "./kube-helpers";
+
+let clusterStore: ClusterStore;
+
+describe("empty config", () => {
+  beforeAll(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({})
+      }
+    }
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterAll(() => {
+    mockFs.restore();
+  })
+
+  it("adds new cluster to store", async () => {
+    const cluster = new Cluster({
+      id: "foo",
+      preferences: {
+        terminalCWD: "/tmp",
+        icon: "data:image/jpeg;base64, iVBORw0KGgoAAAANSUhEUgAAA1wAAAKoCAYAAABjkf5",
+        clusterName: "minikube"
+      },
+      kubeConfigPath: saveConfigToAppFiles("foo", "fancy foo config"),
+      workspace: workspaceStore.currentWorkspaceId
+    });
+    clusterStore.addCluster(cluster);
+    const storedCluster = clusterStore.getById(cluster.id);
+    expect(storedCluster.id).toBe(cluster.id);
+    expect(storedCluster.preferences.terminalCWD).toBe(cluster.preferences.terminalCWD);
+    expect(storedCluster.preferences.icon).toBe(cluster.preferences.icon);
+  })
+
+  it("adds cluster to default workspace", () => {
+    const storedCluster = clusterStore.getById("foo");
+    expect(storedCluster.workspace).toBe("default");
+  })
+
+  it("check if store can contain multiple clusters", () => {
+    const prodCluster = new Cluster({
+      id: "prod",
+      preferences: {
+        clusterName: "prod"
+      },
+      kubeConfigPath: saveConfigToAppFiles("prod", "fancy config"),
+      workspace: "workstation"
+    });
+    const devCluster = new Cluster({
+      id: "dev",
+      preferences: {
+        clusterName: "dev"
+      },
+      kubeConfigPath: saveConfigToAppFiles("dev", "fancy config"),
+      workspace: "workstation"
+    });
+    clusterStore.addCluster(prodCluster);
+    clusterStore.addCluster(devCluster);
+    expect(clusterStore.hasClusters()).toBeTruthy();
+    expect(clusterStore.clusters.size).toBe(3);
+  });
+
+  it("gets clusters by workspaces", () => {
+    const wsClusters = clusterStore.getByWorkspaceId("workstation");
+    const defaultClusters = clusterStore.getByWorkspaceId("default");
+    expect(defaultClusters.length).toBe(1);
+    expect(wsClusters.length).toBe(2);
+    expect(wsClusters[0].id).toBe("prod");
+    expect(wsClusters[1].id).toBe("dev");
+  })
+
+  it("checks if last added cluster becomes active", () => {
+    expect(clusterStore.activeCluster.id).toBe("dev");
+  })
+
+  it("sets active cluster", () => {
+    clusterStore.setActive("foo");
+    expect(clusterStore.activeCluster.id).toBe("foo");
+  })
+
+  it("check if cluster's kubeconfig file saved", () => {
+    const file = saveConfigToAppFiles("boo", "kubeconfig");
+    expect(fs.readFileSync(file, "utf8")).toBe("kubeconfig");
+  })
+
+  it("removes cluster from store", async () => {
+    await clusterStore.removeById("foo");
+    expect(clusterStore.getById("foo")).toBeUndefined();
+  })
+})
+
+describe("config with existing clusters", () => {
+  beforeEach(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({
+          __internal__: {
+            migrations: {
+              version: "99.99.99"
+            }
+          },
+          clusters: [
+            {
+              id: 'cluster1',
+              kubeConfig: 'foo',
+              preferences: { terminalCWD: '/foo' }
+            },
+            {
+              id: 'cluster2',
+              kubeConfig: 'foo2',
+              preferences: { terminalCWD: '/foo2' }
+            }
+          ]
+        })
+      }
+    }
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterEach(() => {
+    mockFs.restore();
+  })
+
+  it("allows to retrieve a cluster", () => {
+    const storedCluster = clusterStore.getById('cluster1');
+    expect(storedCluster.id).toBe('cluster1');
+    expect(storedCluster.preferences.terminalCWD).toBe('/foo');
+  })
+
+  it("allows to delete a cluster", () => {
+    clusterStore.removeById('cluster2');
+    const storedCluster = clusterStore.getById('cluster1');
+    expect(storedCluster).toBeTruthy();
+    const storedCluster2 = clusterStore.getById('cluster2');
+    expect(storedCluster2).toBeUndefined();
+  })
+
+  it("allows getting all of the clusters", async () => {
+    const storedClusters = clusterStore.clustersList;
+    expect(storedClusters[0].id).toBe('cluster1')
+    expect(storedClusters[0].preferences.terminalCWD).toBe('/foo')
+    expect(storedClusters[1].id).toBe('cluster2')
+    expect(storedClusters[1].preferences.terminalCWD).toBe('/foo2')
+  })
+})
+
+describe("pre 2.0 config with an existing cluster", () => {
+  beforeEach(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({
+          __internal__: {
+            migrations: {
+              version: "1.0.0"
+            }
+          },
+          cluster1: 'kubeconfig content'
+        })
+      }
+    };
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterEach(() => {
+    mockFs.restore();
+  })
+
+  it("migrates to modern format with kubeconfig in a file", async () => {
+    const config = clusterStore.clustersList[0].kubeConfigPath;
+    expect(fs.readFileSync(config, "utf8")).toBe("kubeconfig content");
+  })
+})
+
+describe("pre 2.6.0 config with a cluster that has arrays in auth config", () => {
+  beforeEach(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({
+          __internal__: {
+            migrations: {
+              version: "2.4.1"
+            }
+          },
+          cluster1: {
+            kubeConfig: "apiVersion: v1\nclusters:\n- cluster:\n    server: https://10.211.55.6:8443\n  name: minikube\ncontexts:\n- context:\n    cluster: minikube\n    user: minikube\n  name: minikube\ncurrent-context: minikube\nkind: Config\npreferences: {}\nusers:\n- name: minikube\n  user:\n    client-certificate: /Users/kimmo/.minikube/client.crt\n    client-key: /Users/kimmo/.minikube/client.key\n    auth-provider:\n      config:\n        access-token:\n          - should be string\n        expiry:\n          - should be string\n"
+          },
+        })
+      }
+    }
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterEach(() => {
+    mockFs.restore();
+  })
+
+  it("replaces array format access token and expiry into string", async () => {
+    const file = clusterStore.clustersList[0].kubeConfigPath;
+    const config = fs.readFileSync(file, "utf8");
+    const kc = yaml.safeLoad(config);
+    expect(kc.users[0].user['auth-provider'].config['access-token']).toBe("should be string");
+    expect(kc.users[0].user['auth-provider'].config['expiry']).toBe("should be string");
+  })
+})
+
+describe("pre 2.6.0 config with a cluster icon", () => {
+  beforeEach(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({
+          __internal__: {
+            migrations: {
+              version: "2.4.1"
+            }
+          },
+          cluster1: {
+            kubeConfig: "foo",
+            icon: "icon path",
+            preferences: {
+              terminalCWD: "/tmp"
+            }
+          },
+        })
+      }
+    }
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterEach(() => {
+    mockFs.restore();
+  })
+
+  it("moves the icon into preferences", async () => {
+    const storedClusterData = clusterStore.clustersList[0];
+    expect(storedClusterData.hasOwnProperty('icon')).toBe(false);
+    expect(storedClusterData.preferences.hasOwnProperty('icon')).toBe(true);
+    expect(storedClusterData.preferences.icon).toBe("icon path");
+  })
+})
+
+describe("for a pre 2.7.0-beta.0 config without a workspace", () => {
+  beforeEach(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({
+          __internal__: {
+            migrations: {
+              version: "2.6.6"
+            }
+          },
+          cluster1: {
+            kubeConfig: "foo",
+            icon: "icon path",
+            preferences: {
+              terminalCWD: "/tmp"
+            }
+          },
+        })
+      }
+    }
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterEach(() => {
+    mockFs.restore();
+  })
+
+  it("adds cluster to default workspace", async () => {
+    const storedClusterData = clusterStore.clustersList[0];
+    expect(storedClusterData.workspace).toBe('default');
+  })
+})
+
+describe("pre 3.6.0-beta.1 config with an existing cluster", () => {
+  beforeEach(() => {
+    ClusterStore.resetInstance();
+    const mockOpts = {
+      'tmp': {
+        'lens-cluster-store.json': JSON.stringify({
+          __internal__: {
+            migrations: {
+              version: "2.7.0"
+            }
+          },
+          clusters: [
+            {
+              id: 'cluster1',
+              kubeConfig: 'kubeconfig content'
+            }
+          ]
+        })
+      }
+    };
+    mockFs(mockOpts);
+    clusterStore = ClusterStore.getInstance<ClusterStore>();
+    return clusterStore.load();
+  })
+
+  afterEach(() => {
+    mockFs.restore();
+  })
+
+  it("migrates to modern format with kubeconfig in a file", async () => {
+    const config = clusterStore.clustersList[0].kubeConfigPath;
+    expect(fs.readFileSync(config, "utf8")).toBe("kubeconfig content");
+  })
+})
\ No newline at end of file
diff --git a/src/main/cluster.ts b/src/main/cluster.ts
index 1910a4c2ae..5d28d4ba5a 100644
--- a/src/main/cluster.ts
+++ b/src/main/cluster.ts
@@ -78,7 +78,7 @@ export class Cluster implements ClusterModel {
   @action
   updateModel(model: ClusterModel) {
     Object.assign(this, model);
-    this.apiUrl = this.getKubeconfig().getCurrentCluster().server;
+    this.apiUrl = this.getKubeconfig().getCurrentCluster()?.server;
     this.contextName = this.contextName || this.preferences.clusterName;
   }