diff --git a/dmoj/urls.py b/dmoj/urls.py
index df3d293..69558ba 100644
--- a/dmoj/urls.py
+++ b/dmoj/urls.py
@@ -77,7 +77,6 @@ from judge.views.register import ActivationView, RegistrationView
 from judge.views.select2 import (
     AssigneeSelect2View,
     ChatUserSearchSelect2View,
-    CommentSelect2View,
     ContestSelect2View,
     ContestUserSearchSelect2View,
     OrganizationSelect2View,
@@ -1066,9 +1065,6 @@ urlpatterns = [
                 url(
                     r"^contest/$", ContestSelect2View.as_view(), name="contest_select2"
                 ),
-                url(
-                    r"^comment/$", CommentSelect2View.as_view(), name="comment_select2"
-                ),
             ]
         ),
     ),
diff --git a/judge/admin/comments.py b/judge/admin/comments.py
index 0b2a8e1..c33b683 100644
--- a/judge/admin/comments.py
+++ b/judge/admin/comments.py
@@ -12,7 +12,6 @@ class CommentForm(ModelForm):
     class Meta:
         widgets = {
             "author": AdminHeavySelect2Widget(data_view="profile_select2"),
-            "parent": AdminHeavySelect2Widget(data_view="comment_select2"),
         }
         if HeavyPreviewAdminPageDownWidget is not None:
             widgets["body"] = HeavyPreviewAdminPageDownWidget(
@@ -39,7 +38,7 @@ class CommentAdmin(VersionAdmin):
     )
     list_display = ["author", "linked_object", "time"]
     search_fields = ["author__user__username", "body"]
-    readonly_fields = ["score"]
+    readonly_fields = ["score", "parent"]
     actions = ["hide_comment", "unhide_comment"]
     list_filter = ["hidden"]
     actions_on_top = True
diff --git a/judge/admin/interface.py b/judge/admin/interface.py
index e82bb55..b377212 100644
--- a/judge/admin/interface.py
+++ b/judge/admin/interface.py
@@ -53,7 +53,8 @@ class NavigationBarAdmin(DraggableMPTTAdmin):
 class BlogPostForm(ModelForm):
     def __init__(self, *args, **kwargs):
         super(BlogPostForm, self).__init__(*args, **kwargs)
-        self.fields["authors"].widget.can_add_related = False
+        if "authors" in self.fields:
+            self.fields["authors"].widget.can_add_related = False
 
     class Meta:
         widgets = {
diff --git a/judge/utils/problem_data.py b/judge/utils/problem_data.py
index cd11fc4..5cf9fe7 100644
--- a/judge/utils/problem_data.py
+++ b/judge/utils/problem_data.py
@@ -51,7 +51,10 @@ class ProblemDataStorage(FileSystemStorage):
 
     def delete_directory(self, name):
         directory_path = self.path(name)
-        shutil.rmtree(directory_path)
+        try:
+            shutil.rmtree(directory_path)
+        except FileNotFoundError:
+            pass
 
 
 class ProblemDataError(Exception):
diff --git a/judge/views/select2.py b/judge/views/select2.py
index 1aea075..62a850c 100644
--- a/judge/views/select2.py
+++ b/judge/views/select2.py
@@ -98,11 +98,6 @@ class ContestSelect2View(Select2View):
         return q
 
 
-class CommentSelect2View(Select2View):
-    def get_queryset(self):
-        return Comment.objects.filter(page__icontains=self.term)
-
-
 class UserSearchSelect2View(BaseListView):
     paginate_by = 20