diff --git a/.phive/phars.xml b/.phive/phars.xml
index 614d987e..f71aeb33 100644
--- a/.phive/phars.xml
+++ b/.phive/phars.xml
@@ -3,7 +3,7 @@
   <phar name="phpunit" version="~9.6" installed="9.6.34" location="./tools/phpunit" copy="false"/>
   <phar name="phpcbf" version="4" installed="4.0.1" location="./tools/phpcbf" copy="false"/>
   <phar name="phpcs" version="4" installed="4.0.1" location="./tools/phpcs" copy="false"/>
-  <phar name="phpstan" version="^2.0" installed="2.1.50" location="./tools/phpstan" copy="false"/>
+  <phar name="phpstan" version="^2.0" installed="2.1.54" location="./tools/phpstan" copy="false"/>
   <phar name="phan" version="^5.4.3" installed="5.5.2" location="./tools/phan" copy="false"/>
   <phar name="psalm" version="^5.26.1" installed="5.26.1" location="./tools/psalm" copy="false"/>
   <phar name="phpdox" version="^0.12.0" installed="0.12.0" location="./tools/phpdox" copy="false"/>
diff --git a/www/admin/class_test.file.php b/www/admin/class_test.file.php
index 890adad6..52050903 100644
--- a/www/admin/class_test.file.php
+++ b/www/admin/class_test.file.php
@@ -38,6 +38,11 @@ print "GETFILENAMEENDING: $file: " . File::getFilenameEnding($file) . "<br>";
 $file = getcwd() . DIRECTORY_SEPARATOR . 'class_test.file.php';
 print "GETLINESFROMFILE: $file: " . File::getLinesFromFile($file) . "<br>";
 print "MIMEINFO: $file: " . File::getMimeType($file) . "<br>";
+try {
+	print "MIMEINFO: $file: " . File::getMimeType("does_not_exists.txt") . "<br>";
+} catch (\Exception $e) {
+	print "Error: " . get_class($e) . ": " . $e->getMessage() . "<br>";
+}
 
 print "</body></html>";
 
diff --git a/www/lib/CoreLibs/Check/File.php b/www/lib/CoreLibs/Check/File.php
index c8bdc531..a3f42445 100644
--- a/www/lib/CoreLibs/Check/File.php
+++ b/www/lib/CoreLibs/Check/File.php
@@ -58,15 +58,21 @@ class File
 	 * else returns '' for any other finfo read problem
 	 *
 	 * @param  string $read_file File to read, relative or absolute path
-	 * @return string
+	 * @return string mime type
+	 * @throws \UnexpectedValueException if file cannot be read or is not a file
+	 * @throws \RangeException if we cannot get a mime type and throw exception is on
 	 */
 	public static function getMimeType(string $read_file): string
 	{
 		$finfo = new \finfo(FILEINFO_MIME_TYPE);
-		if (!is_file($read_file)) {
+		if (!is_file($read_file) || !is_readable($read_file)) {
 			throw new \UnexpectedValueException('[getMimeType] File not found: ' . $read_file);
 		}
-		return $finfo->file($read_file) ?: '';
+		$mime_type = $finfo->file($read_file);
+		if ($mime_type === false) {
+			throw new \RangeException('[getMimeType] Cannot get mime type for: ' . $read_file);
+		}
+		return $mime_type;
 	}
 }