diff --git a/crates/engine/src/cmd/layer.rs b/crates/engine/src/cmd/layer.rs
index 757de37a7..8b0e9392a 100644
--- a/crates/engine/src/cmd/layer.rs
+++ b/crates/engine/src/cmd/layer.rs
@@ -29,8 +29,8 @@ pub fn specs() -> Vec<CommandSpec> {
             "New Layer…",
             ["Window", "Layers"],
             Some("Cmd+L"),
-            "{name?, top?: bool, below?: bool, color?, template?, locked?, visible?, printable?, preview?, dimImages?} a layer directly above the current layer, at its level (a sublayer beside a current sublayer); `top`: above all layers (Ctrl/Cmd-click the button); `below`: directly below the current layer, at its level (Ctrl/Cmd+Alt-click the button), not with `top`. Options as layer.setProps → {id}",
-            has_doc,
+            "{name?, top?: bool, below?: bool, color?, template?, locked?, visible?, printable?, preview?, dimImages?} a layer directly above the current layer, at its level (a sublayer beside a current sublayer); `top`: above all layers (Ctrl/Cmd-click the button); `below`: directly below the current layer, at its level (Ctrl/Cmd+Alt-click the button), not with `top`. Options as layer.setProps; refused while an opacity mask is edited (the Layers panel lists only the mask) → {id}",
+            super::maskedit::outside_mask_editing,
             new_layer
         ),
         cmd!(
@@ -38,8 +38,8 @@ pub fn specs() -> Vec<CommandSpec> {
             "New Sublayer…",
             ["Window", "Layers"],
             None,
-            "{parent?: layer id (default: the highlighted row's layer, else the current layer), bottom?: bool, name?, …options as layer.new} a sublayer on top of the parent's contents; `bottom`: under the parent's contents, above a clipping layer's clipping path (Ctrl/Cmd+Alt-click the button) → {id}",
-            has_doc,
+            "{parent?: layer id (default: the highlighted row's layer, else the current layer), bottom?: bool, name?, …options as layer.new} a sublayer on top of the parent's contents; `bottom`: under the parent's contents, above a clipping layer's clipping path (Ctrl/Cmd+Alt-click the button); refused while an opacity mask is edited → {id}",
+            super::maskedit::outside_mask_editing,
             new_sublayer
         ),
         cmd!(
diff --git a/crates/engine/src/tests/opacitymask.rs b/crates/engine/src/tests/opacitymask.rs
index 2a8cbf4ca..c2db4f368 100644
--- a/crates/engine/src/tests/opacitymask.rs
+++ b/crates/engine/src/tests/opacitymask.rs
@@ -151,6 +151,23 @@ fn mask_options_already_set_record_no_undo_step() {
     assert!(s.execute("transparency.setOpacityMask", &json!({"id": a.0})).is_err(), "no flag given");
 }
 
+/// #4538: while a mask is edited the Layers panel lists only the mask, so New Layer and New
+/// Sublayer are refused instead of adding layers no row shows; they work again afterwards.
+#[test]
+fn new_layers_are_refused_while_a_mask_is_edited() {
+    let mut s = session();
+    editing_mask(&mut s);
+    let layers = doc(&s).layers.len();
+    for cmd in ["layer.new", "layer.newSublayer"] {
+        assert!(s.execute(cmd, &json!({})).is_err(), "{cmd} while the mask is edited");
+    }
+    assert_eq!(doc(&s).layers.len(), layers);
+    s.execute("transparency.stopEditingOpacityMask", &json!({})).unwrap();
+    let layers = doc(&s).layers.len();
+    s.execute("layer.new", &json!({})).unwrap();
+    assert_eq!(doc(&s).layers.len(), layers + 1);
+}
+
 #[test]
 fn release_while_editing_leaves_editing_first() {
     let mut s = session();
diff --git a/docs/mcp.md b/docs/mcp.md
index 134ae18ad..fc9d738e7 100644
--- a/docs/mcp.md
+++ b/docs/mcp.md
@@ -2225,7 +2225,8 @@ and `layerRows`, the rows highlighted in the panel.
 - **Buttons**: `layer.new {name?, top?, below?, …options}` (above the current layer at its level; `top` with
   Ctrl/Cmd; `below`, directly below the current layer at its level, with Ctrl/Cmd+Alt),
   `layer.newSublayer {parent?, bottom?, name?, …options}` (on top of the parent's contents; `bottom`, under them but
-  above a clipping layer's clipping path, with Ctrl/Cmd+Alt), `layer.delete {ids?}` (rows with what they hold; the
+  above a clipping layer's clipping path, with Ctrl/Cmd+Alt; both refused while an opacity mask is edited),
+  `layer.delete {ids?}` (rows with what they hold; the
   last layer stays), `layer.locate {id?}` (highlights the selected object's row; the panel opens the rows around it)
   and `layer.clippingMask.toggle`.
 - **Panel menu**: `layer.duplicate {ids?}`, `layer.merge {ids?}` (into the layer highlighted last, keeping the