diff --git a/lib/core/ogs-macros.h b/lib/core/ogs-macros.h
index 1b3468d71..b0784324d 100644
--- a/lib/core/ogs-macros.h
+++ b/lib/core/ogs-macros.h
@@ -196,8 +196,8 @@ static ogs_inline ogs_uint24_t ogs_htobe24(ogs_uint24_t x)
                               __switch_p__; \
                               __switch_p__ = 0, __switch_next__ = 1) { {
     #define CASE(X)            } if (!__switch_next__ || \
-                                     !(__switch_next__ = \
-                                         strcmp(__switch_p__, X))) {
+                                     (__switch_next__ = \
+                                         strcmp(__switch_p__, X)) == 0) {
     #define DEFAULT            } {
     #define END          }}}
 #endif
diff --git a/lib/sbi/context.c b/lib/sbi/context.c
index 8559dd726..fb0b24bc1 100644
--- a/lib/sbi/context.c
+++ b/lib/sbi/context.c
@@ -693,12 +693,7 @@ int ogs_sbi_context_parse_config(
                             ogs_yaml_iter_key(&discovery_iter);
                         ogs_assert(discovery_key);
                         if (!strcmp(discovery_key, "delegated")) {
-                            yaml_node_t *discovery_node =
-                                yaml_document_get_node(document,
-                                        discovery_iter.pair->value);
-                            ogs_assert(discovery_node->type ==
-                                    YAML_SCALAR_NODE);
-                            const char* delegated =
+                            const char *delegated =
                                 ogs_yaml_iter_value(&discovery_iter);
                             if (!strcmp(delegated, "auto"))
                                 self.discovery_config.delegated =
@@ -713,8 +708,7 @@ int ogs_sbi_context_parse_config(
                                 ogs_warn("unknown 'delegated' value `%s`",
                                         delegated);
                         } else
-                            ogs_warn("unknown key `%s`",
-                                    discovery_key);
+                            ogs_warn("unknown key `%s`", discovery_key);
                     }
                 }
             }
@@ -732,7 +726,8 @@ void ogs_sbi_add_to_be_notified_nf_type(OpenAPI_nf_type_e nf_type)
     ogs_assert(nf_type);
 
     if (self.num_of_to_be_notified_nf_type < OGS_SBI_MAX_NUM_OF_NF_TYPE) {
-        self.to_be_notified_nf_type[self.num_of_to_be_notified_nf_type] = nf_type;
+        self.to_be_notified_nf_type[self.num_of_to_be_notified_nf_type] =
+            nf_type;
         self.num_of_to_be_notified_nf_type++;
     }
 }
diff --git a/lib/sbi/message.c b/lib/sbi/message.c
index 461540acb..ff3cf675d 100644
--- a/lib/sbi/message.c
+++ b/lib/sbi/message.c
@@ -722,7 +722,7 @@ int ogs_sbi_parse_header(ogs_sbi_message_t *message, ogs_sbi_header_t *header)
     ogs_assert(message);
     ogs_assert(header);
 
-    memset(message, 0, sizeof(*message));
+    memset(message, 0, sizeof(ogs_sbi_message_t));
 
     message->h.method = header->method;
     message->h.uri = header->uri;
diff --git a/lib/sbi/mhd-server.c b/lib/sbi/mhd-server.c
index e22ebc569..5cd84c55e 100644
--- a/lib/sbi/mhd-server.c
+++ b/lib/sbi/mhd-server.c
@@ -371,7 +371,12 @@ static bool server_send_rspmem_persistent(
             hi; hi = ogs_hash_next(hi)) {
         const char *key = ogs_hash_this_key(hi);
         char *val = ogs_hash_this_val(hi);
-        MHD_add_response_header(mhd_response, key, val);
+        ret = MHD_add_response_header(mhd_response, key, val);
+        if (ret != MHD_YES) {
+            ogs_error("MHD_add_response_header failed [%d]", ret);
+            MHD_destroy_response(mhd_response);
+            return false;
+        }
     }
 
     status = response->status;
@@ -386,7 +391,9 @@ static bool server_send_rspmem_persistent(
 
     ret = MHD_queue_response(connection, status, mhd_response);
     if (ret != MHD_YES) {
-        ogs_error("MHD_queue_response_error [%d]", ret);
+        ogs_error("MHD_queue_response failed [%d]", ret);
+        MHD_destroy_response(mhd_response);
+        ogs_pollset_remove(request->poll.write);
         return false;
     }
     MHD_destroy_response(mhd_response);
@@ -562,7 +569,7 @@ suspend:
 
     ogs_assert(server->cb);
     if (server->cb(request, sbi_sess) != OGS_OK) {
-        ogs_error("server callback error");
+        ogs_warn("server callback error");
         ogs_assert(true ==
                 ogs_sbi_server_send_error((ogs_sbi_stream_t *)sbi_sess,
                     OGS_SBI_HTTP_STATUS_INTERNAL_SERVER_ERROR, NULL,