diff --git a/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/main-device/shine_homeserver_main/shine_homeserver_main.ino b/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/main-device/shine_homeserver_main/shine_homeserver_main.ino
index e764e2a..708b358 100644
--- a/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/main-device/shine_homeserver_main/shine_homeserver_main.ino
+++ b/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/main-device/shine_homeserver_main/shine_homeserver_main.ino
@@ -362,6 +362,9 @@ static bool rpcCallSolana(const char *method, const String &paramsJson, String &
 static bool rpcResponseHasError(const String &payload);
 static bool getLatestBlockhashBytes(uint8_t out[32], String &blockhashB58, String &messageOut);
 static bool pdaAlreadyExists(const String &login, String &pdaAddress, String &messageOut);
+static bool extractRpcErrorSummary(const String &payload, String &messageOut);
+static String compactRpcLogs(const String &payload, int maxLines = 3);
+static bool simulateTransactionForError(const String &txBase64, String &messageOut);
 static std::vector<uint8_t> buildLastBlockStateBytes(const String &login, const String &blockchainName);
 static std::vector<uint8_t> buildUnsignedCreateRecord(
     const String &login,
@@ -1223,6 +1226,7 @@ static std::vector<uint8_t> buildCreateInstructionData(
   out.push_back(0);
   out.push_back(1);
   out.push_back(0);
+  out.push_back(0);
   pushStrU8(out, serverAddress);
   out.push_back(0);
   out.push_back(0);
@@ -1298,6 +1302,86 @@ static bool pdaAlreadyExists(const String &login, String &pdaAddress, String &me
   return false;
 }
 
+static String compactRpcLogs(const String &payload, int maxLines) {
+  String out;
+  int pos = payload.indexOf("\"logs\"");
+  if (pos < 0) {
+    return "";
+  }
+  int bracket = payload.indexOf('[', pos);
+  if (bracket < 0) {
+    return "";
+  }
+  int i = bracket + 1;
+  int lines = 0;
+  while (i < (int)payload.length() && lines < maxLines) {
+    while (i < (int)payload.length() && payload[i] != '"' && payload[i] != ']') {
+      i++;
+    }
+    if (i >= (int)payload.length() || payload[i] == ']') {
+      break;
+    }
+    String line;
+    bool escape = false;
+    i++;
+    for (; i < (int)payload.length(); ++i) {
+      char ch = payload[i];
+      if (escape) {
+        switch (ch) {
+          case 'n': line += ' '; break;
+          case 'r': break;
+          case 't': line += ' '; break;
+          default: line += ch; break;
+        }
+        escape = false;
+        continue;
+      }
+      if (ch == '\\') {
+        escape = true;
+        continue;
+      }
+      if (ch == '"') {
+        i++;
+        break;
+      }
+      line += ch;
+    }
+    line.trim();
+    if (!line.isEmpty()) {
+      if (!out.isEmpty()) {
+        out += " | ";
+      }
+      out += line;
+      lines++;
+    }
+  }
+  return out;
+}
+
+static bool extractRpcErrorSummary(const String &payload, String &messageOut) {
+  messageOut = "";
+  String errorMessage;
+  if (jsonStringField(payload, "message", errorMessage) && !errorMessage.isEmpty()) {
+    messageOut = errorMessage;
+  }
+  String logs = compactRpcLogs(payload, 3);
+  if (!logs.isEmpty()) {
+    if (!messageOut.isEmpty()) {
+      messageOut += " | ";
+    }
+    messageOut += logs;
+  }
+  return !messageOut.isEmpty();
+}
+
+static bool simulateTransactionForError(const String &txBase64, String &messageOut) {
+  String payload;
+  if (!rpcCallSolana("simulateTransaction", "[\"" + txBase64 + "\",{\"encoding\":\"base64\",\"sigVerify\":true,\"commitment\":\"processed\"}]", payload)) {
+    return false;
+  }
+  return extractRpcErrorSummary(payload, messageOut);
+}
+
 static std::vector<uint8_t> buildLegacyMessage(
     const uint8_t recentBlockhash[32],
     const uint8_t devicePub[32],
@@ -1531,7 +1615,17 @@ static bool registerHomeserverOnSolana(String &messageOut) {
     return false;
   }
   if (rpcResponseHasError(payload)) {
-    messageOut = "RPC returned sendTransaction error";
+    if (!extractRpcErrorSummary(payload, messageOut)) {
+      messageOut = "RPC returned sendTransaction error";
+    }
+    String simulated;
+    if (simulateTransactionForError(txBase64, simulated)) {
+      if (messageOut.isEmpty()) {
+        messageOut = simulated;
+      } else if (messageOut.indexOf(simulated) < 0) {
+        messageOut += " | simulate: " + simulated;
+      }
+    }
     return false;
   }
   if (!awaitTransactionConfirmation(signatureB58, messageOut)) {
@@ -3085,13 +3179,13 @@ static void actionButtonCb(lv_event_t *event) {
       String registerMessage;
       if (registerHomeserverOnSolana(registerMessage)) {
         gRegisterResultSuccess = true;
-        gRegisterResultMessage = "Registration in SHiNE completed";
-        gRegisterResultDetails = registerMessage;
+        gRegisterResultMessage = registerMessage;
+        gRegisterResultDetails = String("user_pda and tx signature were saved");
         gAccountStatusMessage = "Registration completed";
       } else {
         gRegisterResultSuccess = false;
-        gRegisterResultMessage = "Registration failed";
-        gRegisterResultDetails = registerMessage;
+        gRegisterResultMessage = registerMessage;
+        gRegisterResultDetails = "";
         gAccountStatusMessage = registerMessage;
       }
       gRegisterConfirmMessage = "";
diff --git a/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/reference/shine_homeserver_ui_spec.md b/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/reference/shine_homeserver_ui_spec.md
index 90e96f9..58c1a72 100644
--- a/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/reference/shine_homeserver_ui_spec.md
+++ b/ESP32/esp32/ESP32-S3-Touch-AMOLED-2.16/reference/shine_homeserver_ui_spec.md
@@ -212,7 +212,8 @@
 Поведение:
 
 - после успешной регистрации данные `user_pda` и `tx signature` сохраняются в `NVS`;
-- при ошибке на экране показывается причина отказа.
+- при ошибке на экране показывается причина отказа;
+- если ошибку вернул `sendTransaction`, экран старается показать не только общий текст, но и детали `RPC`/preflight/simulate-логов.
 
 ## Экран STATUS
 
diff --git a/VERSION.properties b/VERSION.properties
index c790f2a..8539140 100644
--- a/VERSION.properties
+++ b/VERSION.properties
@@ -1,2 +1,2 @@
-client.version=1.2.166
-server.version=1.2.155
+client.version=1.2.167
+server.version=1.2.156