diff --git a/Oqtane.Server/Security/PrincipalValidator.cs b/Oqtane.Server/Security/PrincipalValidator.cs
index 1762dab8..0523bd92 100644
--- a/Oqtane.Server/Security/PrincipalValidator.cs
+++ b/Oqtane.Server/Security/PrincipalValidator.cs
@@ -25,7 +25,7 @@ namespace Oqtane.Security
                     if (alias != null)
                     {
                         // verify principal was authenticated for current tenant
-                        if (context.Principal.Claims.First(item => item.Type == ClaimTypes.GroupSid)?.Value != alias.AliasId.ToString())
+                        if (context.Principal.Claims.FirstOrDefault(item => item.Type == ClaimTypes.GroupSid)?.Value != alias.AliasId.ToString())
                         {
                             // tenant agnostic requests must be ignored 
                             string path = context.Request.Path.ToString().ToLower();