diff --git a/phpBB/assets/javascript/installer.js b/phpBB/assets/javascript/installer.js
index e61adc7f99..4930d16901 100644
--- a/phpBB/assets/javascript/installer.js
+++ b/phpBB/assets/javascript/installer.js
@@ -243,8 +243,21 @@
 	 */
 	function parseMessage(messageJSON) {
 		$('#loading_indicator').css('display', 'none');
+		var responseObject;
 
-		var responseObject = JSON.parse(messageJSON);
+		try {
+			responseObject = JSON.parse(messageJSON);
+		}
+		catch (err) {
+			if (window.console) {
+				console.log('Failed to parse JSON object\n\nMessage: ' + err.message + '\n\nServer Response: ' + messageJSON);
+			} else {
+				alert('Failed to parse JSON object\n\nMessage: ' + err.message + '\n\nServer Response: ' + messageJSON);
+			}
+
+			resetPolling();
+			return;
+		}
 
 		// Parse object
 		if (responseObject.hasOwnProperty('errors')) {
diff --git a/phpBB/phpbb/db/migration/tool/module.php b/phpBB/phpbb/db/migration/tool/module.php
index 69ac71abb7..7110760868 100644
--- a/phpBB/phpbb/db/migration/tool/module.php
+++ b/phpBB/phpbb/db/migration/tool/module.php
@@ -262,7 +262,7 @@ class module implements \phpbb\db\migration\tool\tool_interface
 
 			// Success
 			$module_log_name = ((isset($this->user->lang[$data['module_langname']])) ? $this->user->lang[$data['module_langname']] : $data['module_langname']);
-			$phpbb_log->add('admin', $user->data['user_id'], $user->ip, 'LOG_MODULE_ADD', false, array($module_log_name));
+			$phpbb_log->add('admin', ANONYMOUS, $user->ip, 'LOG_MODULE_ADD', false, array($module_log_name));
 
 			// Move the module if requested above/below an existing one
 			if (isset($data['before']) && $data['before'])