From f389ba5214fcf41d613003e31211d6ee2c4536ea Mon Sep 17 00:00:00 2001
From: Yorik van Havre <yorik@uncreated.net>
Date: Sat, 12 Jul 2025 14:49:43 +0200
Subject: [PATCH] BIM: Prevent opening several Layer Managers - issue #17983

---
 src/Mod/BIM/bimcommands/BimLayers.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/Mod/BIM/bimcommands/BimLayers.py b/src/Mod/BIM/bimcommands/BimLayers.py
index 6c5385f0d1..fa2d542051 100644
--- a/src/Mod/BIM/bimcommands/BimLayers.py
+++ b/src/Mod/BIM/bimcommands/BimLayers.py
@@ -68,6 +68,10 @@ class BIM_Layers:
 
         from PySide import QtGui
 
+        # chech if the dialog is running)
+        if getattr(self, "dialog", None):
+            return
+
         # store changes to be committed
         self.deleteList = []
 
@@ -286,7 +290,7 @@ class BIM_Layers:
             doc.recompute()
 
         # exit
-        self.dialog.reject()
+        return self.dialog.reject()
 
     def reject(self):
         "when Cancel button is pressed or dialog is closed"
@@ -296,6 +300,9 @@ class BIM_Layers:
         pref.SetInt("LayersManagerWidth", self.dialog.width())
         pref.SetInt("LayersManagerHeight", self.dialog.height())
 
+        # wipe to let FreeCAD know the dialog has been closed
+        del self.dialog
+
         return True
 
     def update(self):