diff -Nur OpenSim.orig/Framework/Servers/HttpServer/OSHttpServer/HttpClientContext.cs OpenSim/Framework/Servers/HttpServer/OSHttpServer/HttpClientContext.cs
--- OpenSim.orig/Framework/Servers/HttpServer/OSHttpServer/HttpClientContext.cs	2021-08-05 13:44:09.896571627 +0900
+++ OpenSim/Framework/Servers/HttpServer/OSHttpServer/HttpClientContext.cs	2021-08-05 13:43:51.435572375 +0900
@@ -134,7 +134,14 @@
                 {
                     X509Certificate2 _cert2 = new X509Certificate2(_cert1);
                     if (_cert2 != null)
-                        SSLCommonName = _cert2.GetNameInfo(X509NameType.SimpleName, false);
+                    {
+                        try {
+                            SSLCommonName = _cert2.GetNameInfo(X509NameType.SimpleName, false);
+                        }
+                        catch {
+                            SSLCommonName = "unknownName";
+                        }
+                    }
                 }
             }