diff --git a/mailpoet/assets/css/src/components-automation-editor/_errors.scss b/mailpoet/assets/css/src/components-automation-editor/_errors.scss
new file mode 100644
index 0000000000..cd767b18fd
--- /dev/null
+++ b/mailpoet/assets/css/src/components-automation-editor/_errors.scss
@@ -0,0 +1,32 @@
+.mailpoet-automation-errors {
+  padding: 8px 0;
+  width: 280px;
+}
+
+.mailpoet-automation-errors-header {
+  font-weight: 600;
+  padding: 8px 12px;
+}
+
+.mailpoet-automation-step-error {
+  align-items: center;
+  appearance: none;
+  background: none;
+  border: none;
+  cursor: pointer;
+  display: grid;
+  gap: 12px;
+  grid-template-columns: auto 1fr;
+  padding: 9px 12px;
+  text-align: left;
+  width: 100%;
+
+  &:hover {
+    background: #f6f7f7;
+  }
+
+  &:focus-visible {
+    box-shadow: inset 0 0 0 1.5px #2271b1;
+    outline: none;
+  }
+}
diff --git a/mailpoet/assets/css/src/mailpoet-automation-editor.scss b/mailpoet/assets/css/src/mailpoet-automation-editor.scss
index 6488a8e3f2..9f80b897d3 100644
--- a/mailpoet/assets/css/src/mailpoet-automation-editor.scss
+++ b/mailpoet/assets/css/src/mailpoet-automation-editor.scss
@@ -8,6 +8,7 @@
 @import './components-automation-editor/chip';
 @import './components-automation-editor/dropdown';
 @import './components-automation-editor/empty-workflow';
+@import './components-automation-editor/errors';
 @import './components-automation-editor/panel';
 @import './components-automation-editor/separator';
 @import './components-automation-editor/status';
diff --git a/mailpoet/assets/js/src/automation/editor/components/header/errors.tsx b/mailpoet/assets/js/src/automation/editor/components/header/errors.tsx
new file mode 100644
index 0000000000..6f03119fe6
--- /dev/null
+++ b/mailpoet/assets/js/src/automation/editor/components/header/errors.tsx
@@ -0,0 +1,169 @@
+import { ComponentType, useContext, useEffect, useMemo, useState } from 'react';
+import {
+  __unstableComposite as Composite,
+  __unstableCompositeItem as CompositeItem,
+  __unstableUseCompositeState as useCompositeState,
+  Button,
+  Popover as WpPopover,
+} from '@wordpress/components';
+import { useDispatch, useSelect } from '@wordpress/data';
+import { createContext } from '@wordpress/element';
+import { __ } from '@wordpress/i18n';
+import { Chip } from '../chip';
+import { ColoredIcon } from '../icons';
+import {
+  StepError as StepErrorType,
+  stepSidebarKey,
+  storeName,
+} from '../../store';
+
+// properties "offset" and "placement" are missing in WpPopover type definition
+const Popover: ComponentType<
+  WpPopover.Props & {
+    offset?: number;
+    placement?: string;
+  }
+> = WpPopover;
+
+export const ErrorsCompositeContext =
+  createContext<ReturnType<typeof useCompositeState>>(undefined);
+
+type StepErrorProps = {
+  stepId: string;
+};
+
+function StepError({ stepId }: StepErrorProps): JSX.Element {
+  const compositeState = useContext(ErrorsCompositeContext);
+
+  const { steps, workflowData } = useSelect(
+    (select) => ({
+      steps: select(storeName).getSteps(),
+      workflowData: select(storeName).getWorkflowData(),
+    }),
+    [],
+  );
+
+  const { openSidebar, selectStep } = useDispatch(storeName);
+
+  const stepData = workflowData.steps[stepId];
+  const step = steps.find(({ key }) => key === stepData.key);
+
+  return (
+    <CompositeItem
+      className="mailpoet-automation-step-error"
+      role="listitem"
+      state={compositeState}
+      onClick={() => {
+        openSidebar(stepSidebarKey);
+        selectStep(stepData);
+      }}
+    >
+      <ColoredIcon
+        icon={step.icon}
+        foreground={step.foreground}
+        background={step.background}
+        width="23px"
+        height="23px"
+      />
+      {step.title}
+    </CompositeItem>
+  );
+}
+
+export function Errors(): JSX.Element | null {
+  const [showPopover, setShowPopover] = useState(false);
+
+  const compositeState = useCompositeState({
+    orientation: 'vertical',
+    shift: true,
+  });
+
+  const { errors, workflowData } = useSelect(
+    (select) => ({
+      errors: select(storeName).getErrors(),
+      workflowData: select(storeName).getWorkflowData(),
+    }),
+    [],
+  );
+
+  // walk the steps tree (breadth first) to produce stable error order
+  const stepErrors = useMemo(() => {
+    if (!errors) {
+      return [];
+    }
+
+    const visited = new Map<string, StepErrorType | undefined>();
+    const ids = workflowData.steps.root.next_steps.map(({ id }) => id);
+    while (ids.length > 0) {
+      const id = ids.shift();
+      if (!visited.has(id)) {
+        visited.set(id, errors.steps[id]);
+        workflowData.steps[id]?.next_steps?.forEach((step) =>
+          ids.push(step.id),
+        );
+      }
+    }
+    return [...visited.values()].filter((error) => !!error);
+  }, [errors, workflowData]);
+
+  // automatically open the popover when errors appear
+  const hasErrors = stepErrors.length > 0;
+  useEffect(() => {
+    if (hasErrors) {
+      setShowPopover(true);
+    }
+  }, [hasErrors]);
+
+  if (stepErrors.length === 0) {
+    return null;
+  }
+
+  return (
+    <div>
+      <Button
+        variant="link"
+        onClick={() =>
+          setShowPopover((prevState) =>
+            prevState === undefined ? false : !prevState,
+          )
+        }
+        onMouseDown={() =>
+          // Catch and mark a mouse down event from an open popover with "undefined" to avoid closing it
+          // (automatically via click outside) and reopening it right after (via the onClick handler).
+          // The "onClose" method of the popover doesn't pass any events so we can't filter them.
+          setShowPopover((prevState) => (prevState ? undefined : prevState))
+        }
+        style={{ textDecoration: 'none', borderRadius: 99999 }}
+      >
+        <Chip>{stepErrors.length} issues</Chip>
+      </Button>
+      {showPopover && (
+        <Popover
+          offset={10}
+          placement="bottom-end"
+          onClose={() =>
+            setShowPopover((prevState) =>
+              prevState === undefined ? undefined : false,
+            )
+          }
+        >
+          <ErrorsCompositeContext.Provider value={compositeState}>
+            <Composite
+              state={compositeState}
+              role="list"
+              aria-label={__('Workflow errors', 'mailpoet')}
+              className="mailpoet-automation-errors"
+            >
+              <div className="mailpoet-automation-errors-header">
+                {__('The following steps are not fully set:', 'mailpoet')}
+              </div>
+              {stepErrors.map((error) => (
+                <StepError key={error.step_id} stepId={error.step_id} />
+              ))}
+            </Composite>
+          </ErrorsCompositeContext.Provider>
+        </Popover>
+      )}
+    </div>
+  );
+}
diff --git a/mailpoet/assets/js/src/automation/editor/components/header/index.tsx b/mailpoet/assets/js/src/automation/editor/components/header/index.tsx
index cd7f92ddb7..b0e11eb23d 100644
--- a/mailpoet/assets/js/src/automation/editor/components/header/index.tsx
+++ b/mailpoet/assets/js/src/automation/editor/components/header/index.tsx
@@ -3,9 +3,9 @@ import { useDispatch, useSelect } from '@wordpress/data';
 import { PinnedItems } from '@wordpress/interface';
 import { __ } from '@wordpress/i18n';
 import { DocumentActions } from './document_actions';
+import { Errors } from './errors';
 import { InserterToggle } from './inserter_toggle';
 import { MoreMenu } from './more_menu';
-import { Chip } from '../chip';
 import { storeName } from '../../store';
 import { WorkflowStatus } from '../../../listing/workflow';
 
@@ -14,10 +14,22 @@ import { WorkflowStatus } from '../../../listing/workflow';
 //   https://github.com/WordPress/gutenberg/blob/0ee78b1bbe9c6f3e6df99f3b967132fa12bef77d/packages/edit-site/src/components/header/index.js
 
 function ActivateButton(): JSX.Element {
+  const { errors } = useSelect(
+    (select) => ({
+      errors: select(storeName).getErrors(),
+    }),
+    [],
+  );
+
   const { activate } = useDispatch(storeName);
 
   return (
-    <Button isPrimary className="editor-post-publish-button" onClick={activate}>
+    <Button
+      isPrimary
+      className="editor-post-publish-button"
+      onClick={activate}
+      disabled={!!errors}
+    >
       Activate
     </Button>
   );
@@ -49,11 +61,10 @@ type Props = {
 
 export function Header({ showInserterToggle }: Props): JSX.Element {
   const { setWorkflowName } = useDispatch(storeName);
-  const { workflowName, workflowStatus, errors } = useSelect(
+  const { workflowName, workflowStatus } = useSelect(
     (select) => ({
       workflowName: select(storeName).getWorkflowData().name,
       workflowStatus: select(storeName).getWorkflowData().status,
-      errors: select(storeName).getErrors(),
     }),
     [],
   );
@@ -91,9 +102,7 @@ export function Header({ showInserterToggle }: Props): JSX.Element {
 
       <div className="edit-site-header_end">
         <div className="edit-site-header__actions">
-          {errors && Object.values(errors.steps).length > 0 && (
-            <Chip>{Object.values(errors.steps).length} issues</Chip>
-          )}
+          <Errors />
           <SaveDraftButton />
           {workflowStatus !== WorkflowStatus.ACTIVE && <ActivateButton />}
           {workflowStatus === WorkflowStatus.ACTIVE && <UpdateButton />}