diff --git a/index.php b/index.php
index 429358dc..1fe13825 100644
--- a/index.php
+++ b/index.php
@@ -1955,7 +1955,7 @@ function performStep(number, callback) {
 						text += '<br><details><summary>Show detailed response</summary><pre><code>' +
 							escapeHTML(response['detailedResponseText']) + '</code></pre></details>';
 					} else {
-						text = 'The following extra files have been found:<ul>';
+						text = 'Unknown files detected within the installation folder. This can be fixed by manually removing (or moving) these files. The following extra files have been found:<ul>';
 						response['response'].forEach(function(file) {
 							text += '<li>' + escapeHTML(file) + '</li>';
 						});
diff --git a/index.web.php b/index.web.php
index 62495575..32fde905 100644
--- a/index.web.php
+++ b/index.web.php
@@ -730,7 +730,7 @@ function performStep(number, callback) {
 						text += '<br><details><summary>Show detailed response</summary><pre><code>' +
 							escapeHTML(response['detailedResponseText']) + '</code></pre></details>';
 					} else {
-						text = 'The following extra files have been found:<ul>';
+						text = 'Unknown files detected within the installation folder. This can be fixed by manually removing (or moving) these files. The following extra files have been found:<ul>';
 						response['response'].forEach(function(file) {
 							text += '<li>' + escapeHTML(file) + '</li>';
 						});
diff --git a/lib/UpdateCommand.php b/lib/UpdateCommand.php
index 22cc87d0..5db19cc4 100644
--- a/lib/UpdateCommand.php
+++ b/lib/UpdateCommand.php
@@ -251,7 +251,7 @@ protected function execute(InputInterface $input, OutputInterface $output) {
 					if (is_string($result['response'])) {
 						$output->writeln('<error>' . $result['response'] . '</error>');
 					} else {
-						$output->writeln('<error>The following extra files have been found:</error>');
+						$output->writeln('<error>Unknown files detected within the installation folder. This can be fixed by manually removing (or moving) these files. The following extra files have been found:</error>');
 						foreach ($result['response'] as $file) {
 							$output->writeln('<error>    ' . $file . '</error>');
 						}
diff --git a/updater.phar b/updater.phar
index 919ebdb4..4a38828c 100755
Binary files a/updater.phar and b/updater.phar differ