diff --git a/src/blenderbim/blenderbim/bim/module/attribute/ui.py b/src/blenderbim/blenderbim/bim/module/attribute/ui.py
index 1fcb0c13cf..5bdb184576 100644
--- a/src/blenderbim/blenderbim/bim/module/attribute/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/attribute/ui.py
@@ -110,6 +110,8 @@ class BIM_PT_material_attributes(Panel):
 
     @classmethod
     def poll(cls, context):
+        if not IfcStore.get_file():
+            return False
         try:
             return bool(context.active_object.active_material.BIMObjectProperties.ifc_definition_id)
         except:
diff --git a/src/blenderbim/blenderbim/bim/module/classification/ui.py b/src/blenderbim/blenderbim/bim/module/classification/ui.py
index b2fc143c85..4cd3d4595c 100644
--- a/src/blenderbim/blenderbim/bim/module/classification/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/classification/ui.py
@@ -17,6 +17,7 @@
 # You should have received a copy of the GNU General Public License
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
+import blenderbim.bim.module.classification.prop as classification_prop
 from bpy.types import Panel, UIList
 from blenderbim.bim.ifc import IfcStore
 from ifcopenshell.api.classification.data import Data
@@ -104,7 +105,7 @@ class BIM_PT_classification_references(Panel):
         if self.oprops.ifc_definition_id not in Data.products:
             Data.load(IfcStore.get_file(), self.oprops.ifc_definition_id)
 
-        self.draw_add_ui()
+        self.draw_add_ui(context)
 
         reference_ids = Data.products[self.oprops.ifc_definition_id]
         if not reference_ids:
@@ -118,8 +119,8 @@ class BIM_PT_classification_references(Panel):
             else:
                 self.draw_ui(reference_id, reference)
 
-    def draw_add_ui(self):
-        if not self.sprops.available_classifications:
+    def draw_add_ui(self, context):
+        if not classification_prop.getClassifications(self.sprops, context):
             return
 
         name = Data.library_classifications[int(self.sprops.available_classifications)]
diff --git a/src/blenderbim/blenderbim/bim/module/model/pie.py b/src/blenderbim/blenderbim/bim/module/model/pie.py
index 102a1bdb16..5c5480f07f 100644
--- a/src/blenderbim/blenderbim/bim/module/model/pie.py
+++ b/src/blenderbim/blenderbim/bim/module/model/pie.py
@@ -47,8 +47,8 @@ class PieAddOpening(bpy.types.Operator):
                 elif len(obj.children) == 1 and not obj.children[0].BIMObjectProperties.ifc_definition_id:
                     opening_name = obj.children[0].name
                 else:
-                    opj_name = obj.name
-            bpy.ops.bim.add_opening(obj=opj_name, opening=opening_name)
+                    obj_name = obj.name
+            bpy.ops.bim.add_opening(obj=obj_name, opening=opening_name)
         return {"FINISHED"}
 
 
diff --git a/src/blenderbim/blenderbim/bim/module/project/operator.py b/src/blenderbim/blenderbim/bim/module/project/operator.py
index c96a795583..8fd33a8906 100644
--- a/src/blenderbim/blenderbim/bim/module/project/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/project/operator.py
@@ -43,6 +43,7 @@ class CreateProject(bpy.types.Operator):
         return result
 
     def _execute(self, context):
+        active_object = context.view_layer.objects.active
         self.file = IfcStore.get_file()
         if self.file:
             return {"FINISHED"}
@@ -79,6 +80,7 @@ class CreateProject(bpy.types.Operator):
         bpy.ops.bim.assign_object(related_object=building.name, relating_object=site.name)
         bpy.ops.bim.assign_object(related_object=building_storey.name, relating_object=building.name)
 
+        context.view_layer.objects.active = active_object
         return {"FINISHED"}
 
     def get_name(self, ifc_class, name):
diff --git a/src/blenderbim/blenderbim/bim/module/pset/ui.py b/src/blenderbim/blenderbim/bim/module/pset/ui.py
index 5a0d78269c..d7fe3aeddb 100644
--- a/src/blenderbim/blenderbim/bim/module/pset/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/pset/ui.py
@@ -207,7 +207,8 @@ class BIM_PT_material_psets(Panel):
         props = context.active_object.active_material.BIMObjectProperties
         if not props.ifc_definition_id:
             return False
-        if IfcStore.get_file().schema == "IFC2X3":
+        file = IfcStore.get_file()
+        if not file or file.schema == "IFC2X3":
             return False  # We don't support material psets in IFC2X3 because they suck
         if props.ifc_definition_id not in Data.products:
             Data.load(IfcStore.get_file(), props.ifc_definition_id)
diff --git a/src/blenderbim/blenderbim/bim/module/root/prop.py b/src/blenderbim/blenderbim/bim/module/root/prop.py
index 3a003d368e..6a28a40b51 100644
--- a/src/blenderbim/blenderbim/bim/module/root/prop.py
+++ b/src/blenderbim/blenderbim/bim/module/root/prop.py
@@ -72,7 +72,8 @@ def refreshPredefinedTypes(self, context):
     global types_enum
     types_enum.clear()
     enum = getIfcPredefinedTypes(self, context)
-    context.scene.BIMRootProperties.ifc_predefined_type = enum[0][0]
+    if enum:
+        context.scene.BIMRootProperties.ifc_predefined_type = enum[0][0]
 
 
 def getIfcProducts(self, context):
diff --git a/src/blenderbim/blenderbim/bim/module/root/ui.py b/src/blenderbim/blenderbim/bim/module/root/ui.py
index 60e816f496..aa2ea98ec2 100644
--- a/src/blenderbim/blenderbim/bim/module/root/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/root/ui.py
@@ -18,6 +18,7 @@
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
 import bpy
+import blenderbim.bim.module.root.prop as root_prop
 from bpy.types import Panel
 from ifcopenshell.api.root.data import Data
 from blenderbim.bim.ifc import IfcStore
@@ -49,7 +50,9 @@ class BIM_PT_class(Panel):
                 row = self.layout.row(align=True)
                 row.operator("bim.reassign_class", icon="CHECKMARK")
                 row.operator("bim.disable_reassign_class", icon="CANCEL", text="")
-                self.draw_class_dropdowns(context)
+                self.draw_class_dropdowns(
+                    context,
+                    root_prop.getIfcPredefinedTypes(context.scene.BIMRootProperties, context))
             else:
                 data = Data.products[props.ifc_definition_id]
                 name = data["type"]
@@ -72,23 +75,24 @@ class BIM_PT_class(Panel):
                 else:
                     row.operator("bim.unassign_class", icon="X", text="").obj = context.active_object.name
         else:
-            self.draw_class_dropdowns(context)
+            ifc_predefined_types = root_prop.getIfcPredefinedTypes(context.scene.BIMRootProperties, context)
+            self.draw_class_dropdowns(context, ifc_predefined_types)
             row = self.layout.row(align=True)
             op = row.operator("bim.assign_class")
             op.ifc_class = context.scene.BIMRootProperties.ifc_class
-            op.predefined_type = context.scene.BIMRootProperties.ifc_predefined_type
+            op.predefined_type = context.scene.BIMRootProperties.ifc_predefined_type if ifc_predefined_types else ""
             op.userdefined_type = context.scene.BIMRootProperties.ifc_userdefined_type
 
-    def draw_class_dropdowns(self, context):
+    def draw_class_dropdowns(self, context, ifc_predefined_types):
         props = context.scene.BIMRootProperties
         row = self.layout.row()
         row.prop(props, "ifc_product")
         row = self.layout.row()
         row.prop(props, "ifc_class")
-        if props.ifc_predefined_type:
+        if ifc_predefined_types:
             row = self.layout.row()
             row.prop(props, "ifc_predefined_type")
-        if props.ifc_predefined_type == "USERDEFINED":
+        if ifc_predefined_types == "USERDEFINED":
             row = self.layout.row()
             row.prop(props, "ifc_userdefined_type")
         row = self.layout.row()
diff --git a/src/blenderbim/blenderbim/bim/module/spatial/operator.py b/src/blenderbim/blenderbim/bim/module/spatial/operator.py
index e10939a59f..7f8fe7b3aa 100644
--- a/src/blenderbim/blenderbim/bim/module/spatial/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/spatial/operator.py
@@ -134,7 +134,7 @@ class RemoveContainer(bpy.types.Operator):
         return IfcStore.execute_ifc_operator(self, context)
 
     def _execute(self, context):
-        obj = bpy.data.objects.get(self.obj) if self.obj else context.active_object
+        obj = bpy.data.objects.get(self.obj, context.active_object) 
         oprops = obj.BIMObjectProperties
         self.file = IfcStore.get_file()
         ifcopenshell.api.run(
@@ -152,6 +152,7 @@ class RemoveContainer(bpy.types.Operator):
             for collection in obj.users_collection:
                 collection.objects.unlink(obj)
             context.scene.collection.objects.link(obj)
+        context.view_layer.objects.active = obj
         return {"FINISHED"}
 
     def remove_collection(self, parent, child):
@@ -162,6 +163,11 @@ class RemoveContainer(bpy.types.Operator):
 
 
 class CopyToContainer(bpy.types.Operator):
+    """
+    Copies selected objects to selected containers
+    Check the mark next to a container in the container list to select it
+    Several containers can be selected at a time
+    """
     bl_idname = "bim.copy_to_container"
     bl_label = "Copy To Container"
     bl_options = {"REGISTER", "UNDO"}
@@ -172,7 +178,7 @@ class CopyToContainer(bpy.types.Operator):
 
     def _execute(self, context):
         self.file = IfcStore.get_file()
-        objects = [bpy.data.objects.get(self.obj)] if self.obj else context.selected_objects
+        objects = list(bpy.data.objects.get(self.obj, context.selected_objects))
         sprops = context.scene.BIMSpatialProperties
         container_ids = [c.ifc_definition_id for c in sprops.spatial_elements if c.is_selected]
         for obj in objects:
diff --git a/src/blenderbim/blenderbim/bim/module/style/ui.py b/src/blenderbim/blenderbim/bim/module/style/ui.py
index 01273d90bf..a2df554fb5 100644
--- a/src/blenderbim/blenderbim/bim/module/style/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/style/ui.py
@@ -59,6 +59,8 @@ class BIM_PT_style_attributes(Panel):
 
     @classmethod
     def poll(cls, context):
+        if not IfcStore.get_file():
+            return False
         try:
             return bool(context.active_object.active_material.BIMMaterialProperties.ifc_style_id)
         except:
diff --git a/src/blenderbim/blenderbim/bim/module/type/operator.py b/src/blenderbim/blenderbim/bim/module/type/operator.py
index 3d54041ebe..d1a889b459 100644
--- a/src/blenderbim/blenderbim/bim/module/type/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/type/operator.py
@@ -136,13 +136,13 @@ class SelectType(bpy.types.Operator):
 
     def execute(self, context):
         self.file = IfcStore.get_file()
-        related_object = bpy.data.objects.get(self.related_object) if self.related_object else context.active_object
+        related_object = bpy.data.objects.get(self.related_object, context.active_object)
         oprops = related_object.BIMObjectProperties
-        obj = IfcStore.get_element(
-            ifcopenshell.util.element.get_type(self.file.by_id(oprops.ifc_definition_id)).GlobalId
-        )
-        context.view_layer.objects.active = obj
-        obj.select_set(True)
+        element_type = ifcopenshell.util.element.get_type(self.file.by_id(oprops.ifc_definition_id))
+        if element_type is not None:
+            obj = IfcStore.get_element(element_type.GlobalId)
+            context.view_layer.objects.active = obj
+            obj.select_set(True)
         return {"FINISHED"}
 
 
diff --git a/src/blenderbim/blenderbim/bim/module/void/operator.py b/src/blenderbim/blenderbim/bim/module/void/operator.py
index 4185daa588..c41582adeb 100644
--- a/src/blenderbim/blenderbim/bim/module/void/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/void/operator.py
@@ -35,8 +35,10 @@ class AddOpening(bpy.types.Operator):
         return IfcStore.execute_ifc_operator(self, context)
 
     def _execute(self, context):
-        obj = bpy.data.objects.get(self.obj) if self.obj else context.active_object
-        opening = bpy.data.objects.get(self.opening)
+        obj = context.scene.objects.get(self.obj, context.active_object) 
+        opening = context.scene.objects.get(self.opening)
+        if opening is None:
+            return {"FINISHED"}
         opening.display_type = "WIRE"
         if not opening.BIMObjectProperties.ifc_definition_id:
             body_context_id = None
@@ -118,8 +120,10 @@ class AddFilling(bpy.types.Operator):
         return IfcStore.execute_ifc_operator(self, context)
 
     def _execute(self, context):
-        obj = bpy.data.objects.get(self.obj) if self.obj else context.active_object
-        opening = bpy.data.objects.get(self.opening) if self.opening else context.scene.VoidProperties.desired_opening
+        obj = context.scene.objects.get(self.obj, context.active_object) 
+        opening = context.scene.objects.get(self.opening, context.scene.VoidProperties.desired_opening)
+        if opening is None:
+            return {'FINISHED'}
         self.file = IfcStore.get_file()
         element_id = obj.BIMObjectProperties.ifc_definition_id
         ifcopenshell.api.run(
diff --git a/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py b/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py
index b626740cde..a00b623ea5 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py
@@ -63,7 +63,7 @@ class Usecase:
     def get_styled_representation(self, definition_representation):
         representations = [
             r
-            for r in definition_representation.Representations is r.is_a("IfcStyledRepresentation")
+            for r in definition_representation.Representations if r.is_a("IfcStyledRepresentation")
             and r.ContextOfItems == self.settings["context"]
         ]
         if representations: