diff --git a/src/ctx/queue.rs b/src/ctx/queue.rs
index 6b74fd92..39d7e9de 100644
--- a/src/ctx/queue.rs
+++ b/src/ctx/queue.rs
@@ -13,12 +13,16 @@ pub trait Queue<I,O> { //TODO probably remove mandatory StdEnqueueable bound
 pub enum StdEnqueueable<E> where E: Env {
     Render{force: bool},
     Event{event: EEvent<E>, ts: u64},
-    MutateWidget{path: E::WidgetPath, f: fn(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)},
-    MutateWidgetClosure{path: E::WidgetPath, f: Box<dyn FnOnce(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)+'static>},
+    MutateWidget{path: E::WidgetPath, f: fn(Result<WidgetRefMut<E>,GuionError<E>>,&mut E::Context,E::WidgetPath)},
+    MutateWidgetClosure{path: E::WidgetPath, f: Box<dyn FnOnce(Result<WidgetRefMut<E>,GuionError<E>>,&mut E::Context,E::WidgetPath)+'static>},
+    MutateWidgetTry{path: E::WidgetPath, f: fn(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)},
+    MutateWidgetClosureTry{path: E::WidgetPath, f: Box<dyn FnOnce(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)+'static>},
     MutateRoot{f: fn(&mut E::Storage,&mut E::Context)},
     MutateRootClosure{f: Box<dyn FnOnce(&mut E::Storage,&mut E::Context)+'static>},
-    AccessWidget{path: E::WidgetPath, f: fn(WidgetRef<E>,&mut E::Context)},
-    AccessWidgetClosure{path: E::WidgetPath, f: Box<dyn FnOnce(WidgetRef<E>,&mut E::Context)+'static>},
+    AccessWidget{path: E::WidgetPath, f: fn(Result<WidgetRef<E>,GuionError<E>>,&mut E::Context)},
+    AccessWidgetClosure{path: E::WidgetPath, f: Box<dyn FnOnce(Result<WidgetRef<E>,GuionError<E>>,&mut E::Context)+'static>},
+    AccessWidgetTry{path: E::WidgetPath, f: fn(WidgetRef<E>,&mut E::Context)},
+    AccessWidgetClosureTry{path: E::WidgetPath, f: Box<dyn FnOnce(WidgetRef<E>,&mut E::Context)+'static>},
     AccessRoot{f: fn(&E::Storage,&mut E::Context)},
     AccessRootClosure{f: Box<dyn FnOnce(&E::Storage,&mut E::Context)+'static>},
     MutMessage{path: E::WidgetPath, msg: E::Message},
diff --git a/src/widget/link/mod.rs b/src/widget/link/mod.rs
index 8dc6b742..8648a2d6 100644
--- a/src/widget/link/mod.rs
+++ b/src/widget/link/mod.rs
@@ -16,22 +16,40 @@ pub struct Link<'c,E> where E: Env {
 impl<'c,E> Link<'c,E> where E: Env {
     /// Enqueue mutable access to this widget
     #[inline] 
-    pub fn mutate(&mut self, f: fn(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)) {
+    pub fn mutate(&mut self, f: fn(Result<WidgetRefMut<E>,GuionError<E>>,&mut E::Context,E::WidgetPath)) {
         self.mutate_at(f,StdOrder::PostCurrent,0)
     }
     #[inline] 
-    pub fn mutate_at<O>(&mut self, f: fn(WidgetRefMut<E>,&mut E::Context,E::WidgetPath), o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+    pub fn mutate_at<O>(&mut self, f: fn(Result<WidgetRefMut<E>,GuionError<E>>,&mut E::Context,E::WidgetPath), o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
         self.enqueue(StdEnqueueable::MutateWidget{path: self.widget.direct_path.refc(),f},o,p)
     }
     /// Enqueue mutable access to this widget
     #[inline] 
-    pub fn mutate_closure(&mut self, f: Box<dyn FnOnce(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)+'static>) {
+    pub fn mutate_closure(&mut self, f: Box<dyn FnOnce(Result<WidgetRefMut<E>,GuionError<E>>,&mut E::Context,E::WidgetPath)+'static>) {
         self.mutate_closure_at(f,StdOrder::PostCurrent,0)
     }
     #[inline] 
-    pub fn mutate_closure_at<O>(&mut self, f: Box<dyn FnOnce(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)+'static>, o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+    pub fn mutate_closure_at<O>(&mut self, f: Box<dyn FnOnce(Result<WidgetRefMut<E>,GuionError<E>>,&mut E::Context,E::WidgetPath)+'static>, o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
         self.enqueue(StdEnqueueable::MutateWidgetClosure{path: self.widget.direct_path.refc(),f},o,p)
     }
+    /// Enqueue mutable access to this widget
+    #[inline] 
+    pub fn mutate_try(&mut self, f: fn(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)) {
+        self.mutate_at_try(f,StdOrder::PostCurrent,0)
+    }
+    #[inline] 
+    pub fn mutate_at_try<O>(&mut self, f: fn(WidgetRefMut<E>,&mut E::Context,E::WidgetPath), o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+        self.enqueue(StdEnqueueable::MutateWidgetTry{path: self.widget.direct_path.refc(),f},o,p)
+    }
+    /// Enqueue mutable access to this widget
+    #[inline] 
+    pub fn mutate_closure_try(&mut self, f: Box<dyn FnOnce(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)+'static>) {
+        self.mutate_closure_at_try(f,StdOrder::PostCurrent,0)
+    }
+    #[inline] 
+    pub fn mutate_closure_at_try<O>(&mut self, f: Box<dyn FnOnce(WidgetRefMut<E>,&mut E::Context,E::WidgetPath)+'static>, o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+        self.enqueue(StdEnqueueable::MutateWidgetClosureTry{path: self.widget.direct_path.refc(),f},o,p)
+    }
     /// Enqueue message-style invoking of [WidgetMut::message]
     #[inline]
     pub fn message_mut(&mut self, m: E::Message) {
@@ -44,22 +62,40 @@ impl<'c,E> Link<'c,E> where E: Env {
     }
     /// Enqueue immutable access to this widget
     #[inline] 
-    pub fn later(&mut self, f: fn(WidgetRef<E>,&mut E::Context)) {
+    pub fn later(&mut self, f: fn(Result<WidgetRef<E>,GuionError<E>>,&mut E::Context)) {
         self.later_at(f,StdOrder::PostCurrent,0)
     }
     #[inline] 
-    pub fn later_at<O>(&mut self, f: fn(WidgetRef<E>,&mut E::Context), o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+    pub fn later_at<O>(&mut self, f: fn(Result<WidgetRef<E>,GuionError<E>>,&mut E::Context), o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
         self.enqueue(StdEnqueueable::AccessWidget{path: self.widget.direct_path.refc(),f},o,p)
     }
     /// Enqueue immutable access to this widget
     #[inline] 
-    pub fn later_closure(&mut self, f: Box<dyn FnOnce(WidgetRef<E>,&mut E::Context)+Sync>) {
+    pub fn later_closure(&mut self, f: Box<dyn FnOnce(Result<WidgetRef<E>,GuionError<E>>,&mut E::Context)+Sync>) {
         self.later_closure_at(f,StdOrder::PostCurrent,0)
     }
     #[inline] 
-    pub fn later_closure_at<O>(&mut self, f: Box<dyn FnOnce(WidgetRef<E>,&mut E::Context)+Sync>, o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+    pub fn later_closure_at<O>(&mut self, f: Box<dyn FnOnce(Result<WidgetRef<E>,GuionError<E>>,&mut E::Context)+Sync>, o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
         self.enqueue(StdEnqueueable::AccessWidgetClosure{path: self.widget.direct_path.refc(),f},o,p)
     }
+    /// Enqueue immutable access to this widget
+    #[inline] 
+    pub fn later_try(&mut self, f: fn(WidgetRef<E>,&mut E::Context)) {
+        self.later_at_try(f,StdOrder::PostCurrent,0)
+    }
+    #[inline] 
+    pub fn later_at_try<O>(&mut self, f: fn(WidgetRef<E>,&mut E::Context), o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+        self.enqueue(StdEnqueueable::AccessWidgetTry{path: self.widget.direct_path.refc(),f},o,p)
+    }
+    /// Enqueue immutable access to this widget
+    #[inline] 
+    pub fn later_closure_try(&mut self, f: Box<dyn FnOnce(WidgetRef<E>,&mut E::Context)+Sync>) {
+        self.later_closure_at_try(f,StdOrder::PostCurrent,0)
+    }
+    #[inline] 
+    pub fn later_closure_at_try<O>(&mut self, f: Box<dyn FnOnce(WidgetRef<E>,&mut E::Context)+Sync>, o: O, p: i64) where ECQueue<E>: Queue<StdEnqueueable<E>,O> {
+        self.enqueue(StdEnqueueable::AccessWidgetClosureTry{path: self.widget.direct_path.refc(),f},o,p)
+    }
     #[inline]
     pub fn enqueue_invalidate(&mut self) {
         self.enqueue(StdEnqueueable::InvalidateWidget{path: self.widget.direct_path.refc()},StdOrder::PreRender,0)
diff --git a/src/widgets/area/widget.rs b/src/widgets/area/widget.rs
index d2d1929a..1fa21955 100644
--- a/src/widgets/area/widget.rs
+++ b/src/widgets/area/widget.rs
@@ -65,7 +65,7 @@ impl<'w,E,W,Scroll> Widget<E> for Area<'w,E,W,Scroll> where
                     ee.key == EEKey::<E>::UP || ee.key == EEKey::<E>::DOWN ||
                     ee.key == EEKey::<E>::LEFT || ee.key == EEKey::<E>::RIGHT
                 {
-                    l.mutate_closure(Box::new(move |mut w,ctx,_| {
+                    l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                         let w = w.traitcast_mut::<dyn AtomStateMut<E,(u32,u32)>>().unwrap();
                         let mut v = w.get(ctx);
                         if ee.key == EEKey::<E>::UP {
diff --git a/src/widgets/checkbox/widget.rs b/src/widgets/checkbox/widget.rs
index 717f8ecb..5111702e 100644
--- a/src/widgets/checkbox/widget.rs
+++ b/src/widgets/checkbox/widget.rs
@@ -166,7 +166,7 @@ impl<'w,E,State,Text> CheckBox<'w,E,State,Text> where
     Text: AsWidget<E>,
 {
     pub fn set(mut l: Link<E>, v: bool) {
-        l.mutate_closure(Box::new(move |mut w,c,_|{
+        l.mutate_closure_try(Box::new(move |mut w,c,_|{
             //w.traitcast_mut::<dyn AtomStateMut<E,bool>>().unwrap().set(v,c);
             let w = w.traitcast_mut::<dyn ICheckBoxMut<E>>().unwrap();
             w.state_mut().set(v,c);
diff --git a/src/widgets/label/widget.rs b/src/widgets/label/widget.rs
index a83138a5..9706dc19 100644
--- a/src/widgets/label/widget.rs
+++ b/src/widgets/label/widget.rs
@@ -107,7 +107,7 @@ impl<'w,E,Text,GlyphCache> Label<'w,E,Text,GlyphCache> where
         let glyphs = Arc::new(ESGlyphs::<E>::generate(text.as_ref(),(20.0,20.0),l.ctx));
 
         let g = glyphs.refc();
-        l.mutate_closure(Box::new(move |mut w,ctx,_| {
+        l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
             let vali = w.traitcast_mut::<dyn ValidationMut<E>>().unwrap();
             let key = vali.validate();
             let cache = w.traitcast_mut::<dyn AtomStateMut<E,LocalGlyphCache<E>>>().unwrap();
diff --git a/src/widgets/splitpane/widget.rs b/src/widgets/splitpane/widget.rs
index 97e3de24..f4a74e6a 100644
--- a/src/widgets/splitpane/widget.rs
+++ b/src/widgets/splitpane/widget.rs
@@ -88,7 +88,7 @@ impl<'w,E,L,R,V> Widget<E> for SplitPane<'w,E,L,R,V> where
                         cx = cx - wx0;
                         let fcx = (cx as f32)/(ww as f32);
 
-                        l.mutate_closure(Box::new(move |mut w,c,_|{
+                        l.mutate_closure_try(Box::new(move |mut w,c,_|{
                             let w = w.traitcast_mut::<dyn AtomStateMut<E,f32>>().unwrap();
                             w.set(fcx,c);
                         }));
diff --git a/src/widgets/textbox/imp.rs b/src/widgets/textbox/imp.rs
index 14f86330..61dea4c7 100644
--- a/src/widgets/textbox/imp.rs
+++ b/src/widgets/textbox/imp.rs
@@ -170,7 +170,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> TextBox<'w,E,Text,Scroll,Cur
         let glyphs = Arc::new(ESGlyphs::<E>::generate(text.as_ref(),(20.0,20.0),l.ctx));
 
         let g = glyphs.refc();
-        l.mutate_closure(Box::new(move |mut w,ctx,_| {
+        l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
             let vali = w.traitcast_mut::<dyn ValidationMut<E>>().unwrap();
             let key = vali.validate();
             let cache = w.traitcast_mut::<dyn AtomStateMut<E,LocalGlyphCache<E>>>().unwrap();
diff --git a/src/widgets/textbox/widget.rs b/src/widgets/textbox/widget.rs
index c005e984..76f200b7 100644
--- a/src/widgets/textbox/widget.rs
+++ b/src/widgets/textbox/widget.rs
@@ -70,7 +70,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
 
         if let Some(ee) = e.event.is_text_input() {
             let s = ee.text;
-            l.mutate_closure(Box::new(move |mut w,ctx,_| {
+            l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                 let w = w.traitcast_mut::<dyn ITextBoxMut<E>>().unwrap();
                 w.insert_text(&s,ctx);
                 w.scroll_to_cursor(ctx,&b);
@@ -83,7 +83,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
             {
                 let ctrl = l.state().is_pressed(&[EEKey::<E>::CTRL]).is_some();
 
-                l.mutate_closure(Box::new(move |mut w,ctx,_| {
+                l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                     let w = w.traitcast_mut::<dyn ITextBoxMut<E>>().unwrap();
                     if ee.key == EEKey::<E>::BACKSPACE {
                         w.remove_selection_or_n(1,ctx);
@@ -101,7 +101,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
                 }));
                 passed = true;
             }else if ee.key == EEKey::<E>::A && l.state().is_pressed(&[EEKey::<E>::CTRL]).is_some() {
-                l.mutate_closure(Box::new(move |mut w,ctx,_| {
+                l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                     let wc = w.traitcast_mut::<dyn CaptionMut<E>>().unwrap();
                     cursor.select = 0;
                     cursor.caret = wc.len() as u32;
@@ -132,7 +132,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
                     l.clipboard_set_text(text);
 
                     if ee.key == EEKey::<E>::X {
-                        l.mutate_closure(Box::new(move |mut w,ctx,_| {
+                        l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                             let w = w.traitcast_mut::<dyn ITextBoxMut<E>>().unwrap();
                             w.remove_selection(ctx);
                             w.scroll_to_cursor(ctx,&b);
@@ -142,7 +142,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
                 passed = true;
             }else if ee.key == EEKey::<E>::UP || ee.key == EEKey::<E>::DOWN {
                 let b = b.clone();
-                l.mutate_closure(Box::new(move |mut w,ctx,_| {
+                l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                     let w = w.traitcast_mut::<dyn ITextBoxMut<E>>().unwrap();
 
                     if ee.key == EEKey::<E>::UP {
@@ -163,7 +163,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
                 s.off.1 as i32 + ee.y,
             );
             let off = s.bound_off((off.0.max(0) as u32, off.1.max(0) as u32));
-            l.mutate_closure(Box::new(move |mut w,ctx,_| {
+            l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                 let w = w.traitcast_mut::<dyn AtomStateMut<E,(u32,u32)>>().unwrap();
                 w.set(off,ctx);
             }));
@@ -175,7 +175,7 @@ impl<'w,E,Text,Scroll,Curs,CursorStickX,GlyphCache> Widget<E> for TextBox<'w,E,T
                 let mouse_pressed = l.is_hovered() && l.state().is_pressed_and_id(&[EEKey::<E>::MOUSE_LEFT],self.id.clone()).is_some();
                 let b = b.clone();
 
-                l.mutate_closure(Box::new(move |mut w,ctx,_| {
+                l.mutate_closure_try(Box::new(move |mut w,ctx,_| {
                     let w = w.traitcast_mut::<dyn ITextBoxMut<E>>().unwrap();
                     w._m(mouse_down,mouse_pressed,mouse,b,ctx);
                     if mouse_pressed {