diff --git a/src/Core/Addon.php b/src/Core/Addon.php
index 8d1a866915..06f6a12967 100644
--- a/src/Core/Addon.php
+++ b/src/Core/Addon.php
@@ -84,7 +84,7 @@ class Addon
 	public static function getAdminList(): array
 	{
 		$addons_admin = [];
-		$addons = DI::config()->get('addons') ?? [];
+		$addons = array_filter(DI::config()->get('addons') ?? []);
 
 		ksort($addons);
 		foreach ($addons as $name => $data) {
@@ -117,7 +117,7 @@ class Addon
 	 */
 	public static function loadAddons()
 	{
-		self::$addons = array_keys(DI::config()->get('addons') ?? []);
+		self::$addons = array_keys(array_filter(DI::config()->get('addons') ?? []));
 	}
 
 	/**
@@ -192,7 +192,7 @@ class Addon
 	 */
 	public static function reload()
 	{
-		$addons = DI::config()->get('addons') ?? [];
+		$addons = array_filter(DI::config()->get('addons') ?? []);
 
 		foreach ($addons as $name => $data) {
 			$addonname = Strings::sanitizeFilePathItem(trim($name));
@@ -315,7 +315,7 @@ class Addon
 	public static function getVisibleList(): array
 	{
 		$visible_addons = [];
-		$addons = DI::config()->get('addons') ?? [];
+		$addons = array_filter(DI::config()->get('addons') ?? []);
 
 		foreach ($addons as $name => $data) {
 			$visible_addons[] = $name;
diff --git a/src/Core/Config/Util/ConfigFileManager.php b/src/Core/Config/Util/ConfigFileManager.php
index f3627cf477..011dbf0e48 100644
--- a/src/Core/Config/Util/ConfigFileManager.php
+++ b/src/Core/Config/Util/ConfigFileManager.php
@@ -177,7 +177,7 @@ class ConfigFileManager
 	{
 		$filename = $this->configDir . '/' . self::CONFIG_DATA_FILE;
 
-		if (file_exists($filename)) {
+		if (file_exists($filename) && (filesize($filename) > 0)) {
 
 			// The fallback empty return content
 			$content = '<?php return [];';
@@ -188,10 +188,19 @@ class ConfigFileManager
 			 *
 			 * Any exclusive locking (LOCK_EX) would need to wait until all LOCK_SHs are unlocked
 			 */
-			$configStream = fopen($filename, 'r');
+			if (($configStream = @fopen($filename, 'r')) === false) {
+				throw new ConfigFileException(sprintf('Cannot open file "%s" in mode r', $filename));
+			}
+
 			try {
 				if (flock($configStream, LOCK_SH)) {
-					$content = fread($configStream, filesize($filename));
+					clearstatcache(true, $filename);
+
+					if (($filesize = filesize($filename)) === 0) {
+						return;
+					}
+
+					$content = fread($configStream, $filesize);
 					if (!$content) {
 						throw new ConfigFileException(sprintf('Couldn\'t read file %s', $filename));
 					}
diff --git a/src/Core/Config/ValueObject/Cache.php b/src/Core/Config/ValueObject/Cache.php
index 2082511641..61a65c3e70 100644
--- a/src/Core/Config/ValueObject/Cache.php
+++ b/src/Core/Config/ValueObject/Cache.php
@@ -283,7 +283,7 @@ class Cache
 				$keys = array_keys($config[$category]);
 
 				foreach ($keys as $key) {
-					if (!isset($this->config[$category][$key])) {
+					if (!key_exists($key, $this->config[$category] ?? [])) {
 						$return[$category][$key] = $config[$category][$key];
 					}
 				}
@@ -311,6 +311,11 @@ class Cache
 			if (is_array($cache->config[$category])) {
 				$keys = array_keys($cache->config[$category]);
 
+				if (is_null($newConfig[$category] ?? null)) {
+					$newConfig[$category] = [];
+					$newSource[$category] = [];
+				}
+
 				foreach ($keys as $key) {
 					$newConfig[$category][$key] = $cache->config[$category][$key];
 					$newSource[$category][$key] = $cache->source[$category][$key];
diff --git a/src/Module/Api/ApiResponse.php b/src/Module/Api/ApiResponse.php
index 2d54bc1765..b5b2a4717c 100644
--- a/src/Module/Api/ApiResponse.php
+++ b/src/Module/Api/ApiResponse.php
@@ -276,9 +276,8 @@ class ApiResponse extends Response
 				'agent'   => $_SERVER['HTTP_USER_AGENT'] ?? '',
 				'request' => $request,
 			]);
-		$error             = $this->l10n->t('API endpoint %s %s is not implemented', strtoupper($method), $path);
-		$error_description = $this->l10n->t('The API endpoint is currently not implemented but might be in the future.');
+		$error = $this->l10n->t('API endpoint %s %s is not implemented but might be in the future.', strtoupper($method), $path);
 
-		$this->exit('error', ['error' => ['error' => $error, 'error_description' => $error_description]]);
+		$this->error(501, 'Not Implemented', $error);
 	}
 }
diff --git a/src/Module/OStatus/PubSub.php b/src/Module/OStatus/PubSub.php
index c4614855ca..5fbc529836 100644
--- a/src/Module/OStatus/PubSub.php
+++ b/src/Module/OStatus/PubSub.php
@@ -58,7 +58,7 @@ class PubSub extends \Friendica\BaseModule
 
 		$this->logger->info('Feed arrived.', ['from' =>  $this->request->getRemoteAddress(), 'for' => $this->args->getCommand(), 'user-agent' => $this->server['HTTP_USER_AGENT']]);
 		$this->logger->debug('Data stream.', ['xml' => $xml]);
-		$this->logger->debug('Gut request data.', ['request' => $request]);
+		$this->logger->debug('Got request data.', ['request' => $request]);
 
 		$nickname   = $this->parameters['nickname'] ?? '';
 		$contact_id = $this->parameters['cid']      ?? 0;
diff --git a/src/Module/OStatus/PubSubHubBub.php b/src/Module/OStatus/PubSubHubBub.php
index de2104b212..caaa31f98b 100644
--- a/src/Module/OStatus/PubSubHubBub.php
+++ b/src/Module/OStatus/PubSubHubBub.php
@@ -71,7 +71,7 @@ class PubSubHubBub extends \Friendica\BaseModule
 			throw new HTTPException\ForbiddenException();
 		}
 
-		$this->logger->debug('Gut request data.', ['request' => $request]);
+		$this->logger->debug('Got request data.', ['request' => $request]);
 
 		// Subscription request from subscriber
 		// https://pubsubhubbub.github.io/PubSubHubbub/pubsubhubbub-core-0.4.html#rfc.section.5.1
diff --git a/src/Module/OStatus/Salmon.php b/src/Module/OStatus/Salmon.php
index 64dcec22cf..889d852d96 100644
--- a/src/Module/OStatus/Salmon.php
+++ b/src/Module/OStatus/Salmon.php
@@ -65,7 +65,7 @@ class Salmon extends \Friendica\BaseModule
 	protected function post(array $request = [])
 	{
 		$xml = Network::postdata();
-		$this->logger->debug('Gut request data.', ['request' => $request]);
+		$this->logger->debug('Got request data.', ['request' => $request]);
 
 		$nickname = $this->parameters['nickname'] ?? '';
 		if (empty($nickname)) {
diff --git a/src/Object/Api/Mastodon/Instance.php b/src/Object/Api/Mastodon/Instance.php
index fe1a9b3fef..14914cd7fc 100644
--- a/src/Object/Api/Mastodon/Instance.php
+++ b/src/Object/Api/Mastodon/Instance.php
@@ -54,7 +54,7 @@ class Instance extends BaseDataTransferObject
 	protected $urls;
 	/** @var Stats */
 	protected $stats;
-	/** @var string|null */
+	/** @var string|null This is meant as a server banner, default Mastodon "thumbnail" is 1600×620px */
 	protected $thumbnail = null;
 	/** @var array */
 	protected $languages;
@@ -91,7 +91,7 @@ class Instance extends BaseDataTransferObject
 		$this->version           = '2.8.0 (compatible; Friendica ' . App::VERSION . ')';
 		$this->urls              = null; // Not supported
 		$this->stats             = new Stats($config, $database);
-		$this->thumbnail         = $baseUrl->get() . ($config->get('system', 'shortcut_icon') ?? 'images/friendica-32.png');
+		$this->thumbnail         = $baseUrl->get() . 'images/friendica-banner.jpg';
 		$this->languages         = [$config->get('system', 'language')];
 		$this->max_toot_chars    = (int)$config->get('config', 'api_import_size', $config->get('config', 'max_import_size'));
 		$this->registrations     = ($register_policy != Register::CLOSED);
diff --git a/tests/src/Core/Config/Cache/CacheTest.php b/tests/src/Core/Config/Cache/CacheTest.php
index dc9b62dc00..e14b7998c5 100644
--- a/tests/src/Core/Config/Cache/CacheTest.php
+++ b/tests/src/Core/Config/Cache/CacheTest.php
@@ -40,6 +40,7 @@ class CacheTest extends MockedTest
 						'int' => 235,
 						'dec' => 2.456,
 						'array' => ['1', 2, '3', true, false],
+						'null' => null,
 					],
 					'config' => [
 						'a' => 'value',
@@ -503,6 +504,24 @@ class CacheTest extends MockedTest
 					],
 				],
 			],
+			/** @see https://github.com/friendica/friendica/issues/12486#issuecomment-1374609349 */
+			'test_with_null' => [
+				'data'      => [
+					'test_with_null' => null,
+					'config'                => [
+						'register_policy' => 2,
+						'register_text'   => '',
+						'sitename'        => 'Friendica Social Network23',
+						'hostname'        => 'friendica.local',
+						'private_addons'  => false,
+					],
+					'system'                => [
+						'dbclean_expire_conversation' => 90,
+					],
+				],
+				'cat'       => 'test_with_null',
+				'assertion' => null,
+			],
 		];
 	}
 
@@ -511,10 +530,28 @@ class CacheTest extends MockedTest
 	 *
 	 * @dataProvider dataTestCat
 	 */
-	public function testGetCategory(array $data, string $category, array $assertion)
+	public function testGetCategory($data, string $category, $assertion)
 	{
 		$cache = new Cache($data);
 
 		self::assertEquals($assertion, $cache->get($category));
 	}
+
+	/**
+	 * Test that the cache can get merged with different categories
+	 *
+	 * @dataProvider dataTestCat
+	 */
+	public function testCatMerge($data, string $category)
+	{
+		$cache = new Cache($data);
+
+		$newCache = $cache->merge(new Cache([
+			$category => [
+				'new_key' => 'new_value',
+			],
+		]));
+
+		self::assertEquals('new_value', $newCache->get($category, 'new_key'));
+	}
 }
diff --git a/tests/src/Core/Config/Cache/ConfigFileManagerTest.php b/tests/src/Core/Config/Cache/ConfigFileManagerTest.php
index 2adfc27ef7..6c2c41ef65 100644
--- a/tests/src/Core/Config/Cache/ConfigFileManagerTest.php
+++ b/tests/src/Core/Config/Cache/ConfigFileManagerTest.php
@@ -511,4 +511,23 @@ class ConfigFileManagerTest extends MockedTest
 
 		self::assertNull($configCache->get('system', 'default_timezone'));
 	}
+
+	/**
+	 * Test for empty node.config.php
+	 */
+	public function testEmptyFile()
+	{
+		$this->delConfigFile('node.config.php');
+
+		vfsStream::newFile('node.config.php')
+				 ->at($this->root->getChild('config'))
+				 ->setContent('');
+
+		$configFileManager = (new Config())->createConfigFileManager($this->root->url());
+		$configCache       = new Cache();
+
+		$configFileManager->setupCache($configCache);
+
+		self::assertEquals(1,1);
+	}
 }
diff --git a/view/lang/C/messages.po b/view/lang/C/messages.po
index eaf8dacd04..41c14c6149 100644
--- a/view/lang/C/messages.po
+++ b/view/lang/C/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: 2023.03-dev\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2023-01-08 17:39+0000\n"
+"POT-Creation-Date: 2023-01-08 17:47+0000\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -5230,12 +5230,7 @@ msgstr ""
 
 #: src/Module/Api/ApiResponse.php:279
 #, php-format
-msgid "API endpoint %s %s is not implemented"
-msgstr ""
-
-#: src/Module/Api/ApiResponse.php:280
-msgid ""
-"The API endpoint is currently not implemented but might be in the future."
+msgid "API endpoint %s %s is not implemented but might be in the future."
 msgstr ""
 
 #: src/Module/Api/Mastodon/Apps.php:64