diff --git a/src/app/n2n/util/ex/IllegalStateException.php b/src/app/n2n/util/ex/IllegalStateException.php
index <HASH>..<HASH> 100644
--- a/src/app/n2n/util/ex/IllegalStateException.php
+++ b/src/app/n2n/util/ex/IllegalStateException.php
@@ -26,9 +26,9 @@ namespace n2n\util\ex;
  * is not in an appropriate state for the requested operation.

  */

 class IllegalStateException extends \RuntimeException {

-	public static function assertTrue($arg) {

+	public static function assertTrue($arg, string $exMessage = null) {

 		if ($arg === true) return;

 			

-		throw new IllegalStateException();

+		throw new IllegalStateException($exMessage);

 	}

 }
Bs responsive img (MimgBs) added.