Gui: Handle exception when trying to start editing an object

src/Gui/Document.cpp

@@ -648,6 +648,7 @@ bool Document::trySetEdit(Gui::ViewProvider* p, int ModNum, const char *subname)
     Application::Instance->setEditDocument(this);
 
     if (!d->tryStartEditing(vp, obj, _subname.c_str(), ModNum)) {
+        d->setDocumentNameOfTaskDialog(getDocument());
         return false;
     }
 

src/Gui/ViewProvider.cpp

@@ -137,9 +137,14 @@ ViewProvider::~ViewProvider()
 
 ViewProvider *ViewProvider::startEditing(int ModNum)
 {
-    if(setEdit(ModNum)) {
-        _iEditMode = ModNum;
-        return this;
+    try {
+        if (setEdit(ModNum)) {
+            _iEditMode = ModNum;
+            return this;
+        }
+    }
+    catch (const Base::Exception& e) {
+        e.reportException();
     }
     return nullptr;
 }