diff --git a/certbot-apache/certbot_apache/_internal/override_centos.py b/certbot-apache/certbot_apache/_internal/override_centos.py
index de5c31268..9883bb1f1 100644
--- a/certbot-apache/certbot_apache/_internal/override_centos.py
+++ b/certbot-apache/certbot_apache/_internal/override_centos.py
@@ -58,8 +58,13 @@ class CentOSConfigurator(configurator.ApacheConfigurator):
             "rhel", "redhatenterpriseserver", "red hat enterprise linux server",
             "scientific", "scientific linux",
         ]
+        # It is important that the loose version comparison below is not made
+        # if the OS is not RHEL derived. See
+        # https://github.com/certbot/certbot/issues/9481.
+        if not rhel_derived:
+            return False
         at_least_v9 = util.parse_loose_version(os_version) >= util.parse_loose_version('9')
-        return rhel_derived and at_least_v9
+        return at_least_v9
 
     def _override_cmds(self) -> None:
         super()._override_cmds()
diff --git a/certbot-nginx/certbot_nginx/_internal/configurator.py b/certbot-nginx/certbot_nginx/_internal/configurator.py
index 508f50ab7..b91b11a53 100644
--- a/certbot-nginx/certbot_nginx/_internal/configurator.py
+++ b/certbot-nginx/certbot_nginx/_internal/configurator.py
@@ -1060,8 +1060,8 @@ class NginxConfigurator(common.Configurator):
 
         product_name, product_version = version_matches[0]
         if product_name != 'nginx':
-            logger.warning("NGINX derivative %s is not officially supported by"
-                           " certbot", product_name)
+            logger.warning("nginx derivative %s is not officially supported by "
+                           "Certbot.", product_name)
 
         nginx_version = tuple(int(i) for i in product_version.split("."))
 
diff --git a/certbot-nginx/certbot_nginx/_internal/nginxparser.py b/certbot-nginx/certbot_nginx/_internal/nginxparser.py
index 1c74cd367..99955447a 100644
--- a/certbot-nginx/certbot_nginx/_internal/nginxparser.py
+++ b/certbot-nginx/certbot_nginx/_internal/nginxparser.py
@@ -33,6 +33,18 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
+class UnsupportedDirectiveException(RuntimeError):
+    """Exception when encountering an nginx directive which is not supported
+    by this parser."""
+
+    directive_name: str
+    line_no: int
+
+    def __init__(self, directive_name: str, line_no: int) -> None:
+        self.directive_name = directive_name
+        self.line_no = line_no
+
+
 class RawNginxParser:
     # pylint: disable=pointless-statement
     """A class that parses nginx configuration with pyparsing."""
@@ -74,6 +86,7 @@ class RawNginxParser:
 
     def __init__(self, source: str) -> None:
         self.source = source
+        self.whitespace_token_group.addParseAction(self._check_disallowed_directive)
 
     def parse(self) -> ParseResults:
         """Returns the parsed tree."""
@@ -83,6 +96,12 @@ class RawNginxParser:
         """Returns the parsed tree as a list."""
         return self.parse().asList()
 
+    def _check_disallowed_directive(self, _source: str, line: int, results: ParseResults) -> None:
+        # *_by_lua_block might be first or second result, due to optional leading whitespace
+        toks = [t for t in results[0:2] if isinstance(t, str) and t.endswith("_by_lua_block")]
+        if toks:
+            raise UnsupportedDirectiveException(toks[0], line)
+
 
 class RawNginxDumper:
     """A class that dumps nginx configuration from the provided tree."""
diff --git a/certbot-nginx/certbot_nginx/_internal/parser.py b/certbot-nginx/certbot_nginx/_internal/parser.py
index e60d66eb2..bc1643426 100644
--- a/certbot-nginx/certbot_nginx/_internal/parser.py
+++ b/certbot-nginx/certbot_nginx/_internal/parser.py
@@ -223,6 +223,12 @@ class NginxParser:
                                "supported.", item)
             except pyparsing.ParseException as err:
                 logger.warning("Could not parse file: %s due to %s", item, err)
+            except nginxparser.UnsupportedDirectiveException as e:
+                logger.warning(
+                    "%s:%d contained the '%s' directive, which is not supported by Certbot. The "
+                    "file has been ignored, which may prevent Certbot from functioning properly. "
+                    "Consider using the --webroot plugin and manually installing the certificate.",
+                    item, e.line_no, e.directive_name)
         return trees
 
     def _find_config_root(self) -> str:
diff --git a/certbot-nginx/tests/nginxparser_test.py b/certbot-nginx/tests/nginxparser_test.py
index d8f0a5909..3713f16e4 100644
--- a/certbot-nginx/tests/nginxparser_test.py
+++ b/certbot-nginx/tests/nginxparser_test.py
@@ -12,6 +12,7 @@ from certbot_nginx._internal.nginxparser import load
 from certbot_nginx._internal.nginxparser import loads
 from certbot_nginx._internal.nginxparser import RawNginxParser
 from certbot_nginx._internal.nginxparser import UnspacedList
+from certbot_nginx._internal.nginxparser import UnsupportedDirectiveException
 import test_util as util
 
 FIRST = operator.itemgetter(0)
@@ -354,6 +355,69 @@ class TestRawNginxParser(unittest.TestCase):
         parsed = loads("")
         self.assertEqual(parsed, [])
 
+    def test_lua(self):
+        # https://github.com/certbot/certbot/issues/9066
+        self.assertRaises(UnsupportedDirectiveException, loads, """
+        location /foo {
+            content_by_lua_block {
+                ngx.say('Hello World')
+            }
+        }
+        """)
+
+        # Without leading whitespace
+        self.assertRaises(UnsupportedDirectiveException, loads, """
+        location /foo {content_by_lua_block {
+                ngx.say('Hello World')
+            }
+        }
+        """)
+
+        # Doesn't trigger if it's commented or not in the right position.
+        parsed = loads("""
+        location /foo {server_name content_by_lua_block;
+            #content_by_lua_block {
+            # ngx.say('Hello World')
+            # }
+        }
+        """)
+        self.assertEqual(
+            parsed,
+            [
+                [['location', '/foo'],
+                [['server_name', 'content_by_lua_block'],
+                 ['#', 'content_by_lua_block {'],
+                 ['#', " ngx.say('Hello World')"],
+                 ['#', ' }']
+                ]]
+            ])
+
+        # *_by_lua should parse successfully.
+        parsed = loads("""
+            location / {
+                set $a 32;
+                set $b 56;
+                set_by_lua $sum
+                    'return tonumber(ngx.arg[1]) + tonumber(ngx.arg[2])'
+                    $a $b;
+                content_by_lua '
+                    ngx.say("foo");
+                ';
+            }
+        """)
+        self.assertEqual(
+            parsed,
+            [
+                [['location', '/'],
+                 [['set', '$a', '32'],
+                  ['set', '$b', '56'],
+                  ['set_by_lua', '$sum',
+                   "'return tonumber(ngx.arg[1]) + tonumber(ngx.arg[2])'", '$a', '$b'
+                  ],
+                  ['content_by_lua', '\'\n                    ngx.say("foo");\n                \'']
+                 ]]
+            ]
+        )
 
 class TestUnspacedList(unittest.TestCase):
     """Test the UnspacedList data structure"""
diff --git a/certbot-nginx/tests/parser_test.py b/certbot-nginx/tests/parser_test.py
index 7d5b5e669..93a8dcedc 100644
--- a/certbot-nginx/tests/parser_test.py
+++ b/certbot-nginx/tests/parser_test.py
@@ -4,6 +4,7 @@ import re
 import shutil
 import unittest
 from typing import List
+from unittest import mock
 
 from certbot import errors
 from certbot.compat import os
@@ -532,6 +533,14 @@ class NginxParserTest(util.NginxTest):
             for output in log.output
         ))
 
+    @mock.patch('certbot_nginx._internal.parser.logger.warning')
+    def test_load_unsupported_directive_logged(self, mock_warn):
+        nparser = parser.NginxParser(self.config_path)
+        nparser.config_root = nparser.abs_path('unsupported_directives.conf')
+        nparser.load()
+        self.assertEqual(mock_warn.call_count, 1)
+        self.assertIn("which is not supported by Certbot", mock_warn.call_args[0][0])
+
 
 if __name__ == "__main__":
     unittest.main()  # pragma: no cover
diff --git a/certbot-nginx/tests/testdata/etc_nginx/unsupported_directives.conf b/certbot-nginx/tests/testdata/etc_nginx/unsupported_directives.conf
new file mode 100644
index 000000000..d071c68c1
--- /dev/null
+++ b/certbot-nginx/tests/testdata/etc_nginx/unsupported_directives.conf
@@ -0,0 +1,11 @@
+# This configuration file contains unsupported direcives.
+
+server {
+    listen 80;
+
+    location / {
+        foobar_by_lua_block {
+            ngx.say("Hello World")
+        }
+    }
+}
diff --git a/certbot/CHANGELOG.md b/certbot/CHANGELOG.md
index 8ab011f50..177ab0926 100644
--- a/certbot/CHANGELOG.md
+++ b/certbot/CHANGELOG.md
@@ -14,7 +14,14 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 
 ### Fixed
 
-*
+* Interfaces which plugins register themselves as implementing without inheriting from them now show up in `certbot plugins` output.
+* `IPluginFactory`, `IPlugin`, `IAuthenticator` and `IInstaller` have been re-added to
+  `certbot.interfaces`.
+    - This is to fix compatibility with a number of third-party DNS plugins which may
+      have started erroring with `AttributeError` in Certbot v2.0.0.
+    - Plugin authors can find more information about Certbot 2.x compatibility
+      [here](https://github.com/certbot/certbot/wiki/Certbot-v2.x-Plugin-Compatibility).
+* A bug causing our certbot-apache tests to crash on some systems has been resolved.
 
 More details about these changes can be found on our GitHub repo.
 
diff --git a/certbot/certbot/_internal/plugins/disco.py b/certbot/certbot/_internal/plugins/disco.py
index 62e75ead1..5e767ae6d 100644
--- a/certbot/certbot/_internal/plugins/disco.py
+++ b/certbot/certbot/_internal/plugins/disco.py
@@ -24,25 +24,9 @@ from certbot.errors import Error
 
 logger = logging.getLogger(__name__)
 
-PREFIX_FREE_DISTRIBUTIONS = [
-    "certbot",
-    "certbot-apache",
-    "certbot-dns-cloudflare",
-    "certbot-dns-digitalocean",
-    "certbot-dns-dnsimple",
-    "certbot-dns-dnsmadeeasy",
-    "certbot-dns-gehirn",
-    "certbot-dns-google",
-    "certbot-dns-linode",
-    "certbot-dns-luadns",
-    "certbot-dns-nsone",
-    "certbot-dns-ovh",
-    "certbot-dns-rfc2136",
-    "certbot-dns-route53",
-    "certbot-dns-sakuracloud",
-    "certbot-nginx",
-]
-"""Distributions for which prefix will be omitted."""
+
+PLUGIN_INTERFACES = [interfaces.Authenticator, interfaces.Installer, interfaces.Plugin]
+"""Interfaces that should be listed in `certbot plugins` output"""
 
 
 class PluginEntryPoint:
@@ -165,8 +149,8 @@ class PluginEntryPoint:
             "* {0}".format(self.name),
             "Description: {0}".format(self.plugin_cls.description),
             "Interfaces: {0}".format(", ".join(
-                cls.__name__ for cls in self.plugin_cls.mro()
-                if cls.__module__ == 'certbot.interfaces'
+                iface.__name__ for iface in PLUGIN_INTERFACES
+                if issubclass(self.plugin_cls, iface)
             )),
             "Entry point: {0}".format(self.entry_point),
         ]
diff --git a/certbot/certbot/interfaces.py b/certbot/certbot/interfaces.py
index 84223b6c0..176f1a21c 100644
--- a/certbot/certbot/interfaces.py
+++ b/certbot/certbot/interfaces.py
@@ -16,6 +16,11 @@ from acme.client import ClientV2
 from certbot import configuration
 from certbot.achallenges import AnnotatedChallenge
 
+try:
+    from zope.interface import Interface as ZopeInterface
+except ImportError:
+    ZopeInterface = object
+
 if TYPE_CHECKING:
     from certbot._internal.account import Account
 
@@ -465,3 +470,16 @@ class RenewDeployer(metaclass=ABCMeta):
         :type lineage: RenewableCert
 
         """
+
+
+class IPluginFactory(ZopeInterface):
+    """Compatibility shim for plugins that still use Certbot's old zope.interface classes."""
+
+class IPlugin(ZopeInterface):
+    """Compatibility shim for plugins that still use Certbot's old zope.interface classes."""
+
+class IAuthenticator(IPlugin):
+    """Compatibility shim for plugins that still use Certbot's old zope.interface classes."""
+
+class IInstaller(IPlugin):
+    """Compatibility shim for plugins that still use Certbot's old zope.interface classes."""
diff --git a/certbot/tests/plugins/disco_test.py b/certbot/tests/plugins/disco_test.py
index 17677792f..673a8d04b 100644
--- a/certbot/tests/plugins/disco_test.py
+++ b/certbot/tests/plugins/disco_test.py
@@ -152,6 +152,12 @@ class PluginEntryPointTest(unittest.TestCase):
         self.assertIs(self.plugin_ep.misconfigured, False)
         self.assertIs(self.plugin_ep.available, False)
 
+    def test_str(self):
+        output = str(self.plugin_ep)
+        self.assertIn("Authenticator", output)
+        self.assertNotIn("Installer", output)
+        self.assertIn("Plugin", output)
+
     def test_repr(self):
         self.assertEqual("PluginEntryPoint#sa", repr(self.plugin_ep))