diff --git a/lms/djangoapps/courseware/unit_render.py b/lms/djangoapps/courseware/unit_render.py
index aaa70bb36ffe..6580e4c2b477 100644
--- a/lms/djangoapps/courseware/unit_render.py
+++ b/lms/djangoapps/courseware/unit_render.py
@@ -10,7 +10,7 @@
 from rest_framework.decorators import api_view
 from rest_framework.exceptions import ValidationError
 from xblock.fields import Scope
-from xblock.core import XBlock2
+from xblock.core import XBlock, XBlock2Mixin
 
 from lms.djangoapps.course_blocks.api import get_course_blocks
 from lms.djangoapps.courseware.models import StudentModule, XModuleUserStateSummaryField
@@ -66,11 +66,10 @@ def get_unit_blocks(request, usage_id):
                 "block_type": usage_key.block_type,
             }
             try:
-                block_class = XBlock2.load_class(usage_key.block_type, fallback_to_v1=True)
-                if issubclass(block_class, XBlock2):
+                block_class = XBlock.load_class(usage_key.block_type)
+                if issubclass(block_class, XBlock2Mixin):
                     block_data_out["xblock_api_version"] = 2
                     block_data_out["content_fields"] = {}
-                    block_data_out["system_fields"] = {}
                     block_data_out["user_fields"] = {}
 
                     def add_field(field_name, value):
diff --git a/lms/urls.py b/lms/urls.py
index 2bf7dcafae05..2ec140b6417f 100644
--- a/lms/urls.py
+++ b/lms/urls.py
@@ -38,7 +38,7 @@
 from openedx.core.apidocs import api_info
 from openedx.core.djangoapps.auth_exchange.views import LoginWithAccessTokenView
 from openedx.core.djangoapps.catalog.models import CatalogIntegration
-from openedx.core.djangoapps.common_views.xblock import xblock_resource, xblock_resource_v2
+from openedx.core.djangoapps.common_views.xblock import xblock_resource
 from openedx.core.djangoapps.cors_csrf import views as cors_csrf_views
 from openedx.core.djangoapps.course_groups import views as course_groups_views
 from openedx.core.djangoapps.debug import views as openedx_debug_views
@@ -354,11 +354,6 @@
         xblock_resource,
         name='xblock_resource_url',
     ),
-    re_path(
-        r'xblock/resource-v2/(?P<block_type>[^/]+)/(?P<uri>.*)$',
-        xblock_resource_v2,
-        name='xblock_resource_url_v2',
-    ),
 
     # New (Learning-Core-based) XBlock REST API
     path('', include(('openedx.core.djangoapps.xblock.rest_api.urls', 'openedx.core.djangoapps.xblock'),
diff --git a/openedx/core/djangoapps/common_views/xblock.py b/openedx/core/djangoapps/common_views/xblock.py
index a89e6142409a..f45ed0769ff1 100644
--- a/openedx/core/djangoapps/common_views/xblock.py
+++ b/openedx/core/djangoapps/common_views/xblock.py
@@ -12,17 +12,14 @@
 log = logging.getLogger(__name__)
 
 
-def xblock_resource(request, block_type, uri, xblock_version=1):  # pylint: disable=unused-argument
+def xblock_resource(request, block_type, uri):  # pylint: disable=unused-argument
     """
     Return a package resource for the specified XBlock.
     """
     try:
         # Figure out what the XBlock class is from the block type, and
         # then open whatever resource has been requested.
-        if xblock_version == 2:
-            xblock_class = XBlock2.load_class(block_type)
-        else:
-            xblock_class = XBlock.load_class(block_type)
+        xblock_class = XBlock.load_class(block_type)
         content = xblock_class.open_local_resource(uri)
     except OSError:
         log.info('Failed to load xblock resource', exc_info=True)
@@ -33,10 +30,3 @@ def xblock_resource(request, block_type, uri, xblock_version=1):  # pylint: disa
 
     mimetype, _ = mimetypes.guess_type(uri)
     return HttpResponse(content, content_type=mimetype)
-
-
-def xblock_resource_v2(request, block_type, uri):
-    """
-    Return a package resource for the specified v2 XBlock.
-    """
-    return xblock_resource(request, block_type, uri, xblock_version=2)
diff --git a/xmodule/html_block.py b/xmodule/html_block.py
index d612f66367a2..2bdcd8922641 100644
--- a/xmodule/html_block.py
+++ b/xmodule/html_block.py
@@ -353,17 +353,11 @@ def index_dictionary(self):
 
 
 @edxnotes
-class HtmlBlock(HtmlBlockMixin):  # lint-amnesty, pylint: disable=abstract-method
+class HtmlBlock(XBlock2Mixin, HtmlBlockMixin):  # lint-amnesty, pylint: disable=abstract-method
     """
     This is the actual HTML XBlock.
     Nothing extra is required; this is just a wrapper to include edxnotes support.
     """
-
-
-class HtmlBlockV2(XBlock2Mixin, HtmlBlockMixin):
-    """
-    The new version of the HTML block.
-    """
     resources_dir = "assets/html"
 
 
diff --git a/xmodule/x_module.py b/xmodule/x_module.py
index d25012275a5e..c7fcd5e7056a 100644
--- a/xmodule/x_module.py
+++ b/xmodule/x_module.py
@@ -17,7 +17,7 @@
 from web_fragments.fragment import Fragment
 from webob import Response
 from webob.multidict import MultiDict
-from xblock.core import XBlock, XBlockAside
+from xblock.core import XBlock, XBlock2Mixin, XBlockAside
 from xblock.fields import (
     Dict,
     Float,
@@ -586,28 +586,34 @@ def bind_for_student(self, user_id, wrappers=None):
             if getattr(self.runtime, 'position', None):
                 self.position = self.runtime.position   # update the position of the tab
             return
+        
+        if isinstance(self, XBlock2Mixin):
+            if self.scope_ids.user_id is not None:
+                raise RuntimeError("v2 XBlocks cannot be rebound to a different user")
+            # Update scope_ids to point to the new user.
+            self.scope_ids = self.scope_ids._replace(user_id=user_id)
+        else:
+            # If we are switching users mid-request, save the data from the old user.
+            self.save()
 
-        # If we are switching users mid-request, save the data from the old user.
-        self.save()
-
-        # Update scope_ids to point to the new user.
-        self.scope_ids = self.scope_ids._replace(user_id=user_id)
+            # Update scope_ids to point to the new user.
+            self.scope_ids = self.scope_ids._replace(user_id=user_id)
 
-        # Clear out any cached instantiated children.
-        self.clear_child_cache()
+            # Clear out any cached instantiated children.
+            self.clear_child_cache()
 
-        # Clear out any cached field data scoped to the old user.
-        for field in self.fields.values():  # lint-amnesty, pylint: disable=no-member
-            if field.scope in (Scope.parent, Scope.children):
-                continue
+            # Clear out any cached field data scoped to the old user.
+            for field in self.fields.values():  # lint-amnesty, pylint: disable=no-member
+                if field.scope in (Scope.parent, Scope.children):
+                    continue
 
-            if field.scope.user == UserScope.ONE:
-                field._del_cached_value(self)  # pylint: disable=protected-access
-                # not the most elegant way of doing this, but if we're removing
-                # a field from the module's field_data_cache, we should also
-                # remove it from its _dirty_fields
-                if field in self._dirty_fields:
-                    del self._dirty_fields[field]
+                if field.scope.user == UserScope.ONE:
+                    field._del_cached_value(self)  # pylint: disable=protected-access
+                    # not the most elegant way of doing this, but if we're removing
+                    # a field from the module's field_data_cache, we should also
+                    # remove it from its _dirty_fields
+                    if field in self._dirty_fields:
+                        del self._dirty_fields[field]
 
         if wrappers:
             # Put user-specific wrappers around the field-data service for this block.