diff --git a/.eslintignore b/.eslintignore
index 0a3500e28..91cc4695e 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -578,6 +578,9 @@ packages/app-desktop/gui/ResizableLayout/utils/persist.test.js.map
 packages/app-desktop/gui/ResizableLayout/utils/removeItem.d.ts
 packages/app-desktop/gui/ResizableLayout/utils/removeItem.js
 packages/app-desktop/gui/ResizableLayout/utils/removeItem.js.map
+packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.d.ts
+packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.js
+packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.js.map
 packages/app-desktop/gui/ResizableLayout/utils/setLayoutItemProps.d.ts
 packages/app-desktop/gui/ResizableLayout/utils/setLayoutItemProps.js
 packages/app-desktop/gui/ResizableLayout/utils/setLayoutItemProps.js.map
diff --git a/.gitignore b/.gitignore
index bc446bd25..b5a6d14c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -564,6 +564,9 @@ packages/app-desktop/gui/ResizableLayout/utils/persist.test.js.map
 packages/app-desktop/gui/ResizableLayout/utils/removeItem.d.ts
 packages/app-desktop/gui/ResizableLayout/utils/removeItem.js
 packages/app-desktop/gui/ResizableLayout/utils/removeItem.js.map
+packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.d.ts
+packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.js
+packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.js.map
 packages/app-desktop/gui/ResizableLayout/utils/setLayoutItemProps.d.ts
 packages/app-desktop/gui/ResizableLayout/utils/setLayoutItemProps.js
 packages/app-desktop/gui/ResizableLayout/utils/setLayoutItemProps.js.map
diff --git a/packages/app-desktop/gui/MainScreen/MainScreen.tsx b/packages/app-desktop/gui/MainScreen/MainScreen.tsx
index d0050851e..c4c9154d8 100644
--- a/packages/app-desktop/gui/MainScreen/MainScreen.tsx
+++ b/packages/app-desktop/gui/MainScreen/MainScreen.tsx
@@ -34,6 +34,7 @@ import ShareFolderDialog from '../ShareFolderDialog/ShareFolderDialog';
 import { ShareInvitation } from '@joplin/lib/services/share/reducer';
 import ShareService from '@joplin/lib/services/share/ShareService';
 import { reg } from '@joplin/lib/registry';
+import removeKeylessItems from '../ResizableLayout/utils/removeKeylessItems';
 
 const { connect } = require('react-redux');
 const { PromptDialog } = require('../PromptDialog.min.js');
@@ -234,6 +235,14 @@ class MainScreenComponent extends React.Component<Props, State> {
 		try {
 			output = loadLayout(Object.keys(userLayout).length ? userLayout : null, defaultLayout, rootLayoutSize);
 
+			// For unclear reasons, layout items sometimes end up witout a key.
+			// In that case, we can't do anything with them, so remove them
+			// here. It could be due to the deprecated plugin API, which allowed
+			// creating panel without a key, although in this case it should
+			// have been set automatically.
+			// https://github.com/laurent22/joplin/issues/4926
+			output = removeKeylessItems(output);
+
 			if (!findItemByKey(output, 'sideBar') || !findItemByKey(output, 'noteList') || !findItemByKey(output, 'editor')) {
 				throw new Error('"sideBar", "noteList" and "editor" must be present in the layout');
 			}
diff --git a/packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.ts b/packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.ts
new file mode 100644
index 000000000..0faf5971b
--- /dev/null
+++ b/packages/app-desktop/gui/ResizableLayout/utils/removeKeylessItems.ts
@@ -0,0 +1,30 @@
+import produce from 'immer';
+import iterateItems from './iterateItems';
+import { LayoutItem } from './types';
+import validateLayout from './validateLayout';
+
+interface ItemToRemove {
+	parent: LayoutItem;
+	index: number;
+}
+
+export default function(layout: LayoutItem): LayoutItem {
+	const itemsToRemove: ItemToRemove[] = [];
+
+	const output = produce(layout, (layoutDraft: LayoutItem) => {
+		iterateItems(layoutDraft, (itemIndex: number, item: LayoutItem, parent: LayoutItem) => {
+			if (!item.key) itemsToRemove.push({ parent, index: itemIndex });
+			return true;
+		});
+
+		itemsToRemove.sort((a: ItemToRemove, b: ItemToRemove) => {
+			return a.index > b.index ? -1 : +1;
+		});
+
+		for (const item of itemsToRemove) {
+			item.parent.children.splice(item.index, 1);
+		}
+	});
+
+	return output !== layout ? validateLayout(output) : layout;
+}