diff --git a/blockchain-explorer/blockchain-explorer-http.cpp b/blockchain-explorer/blockchain-explorer-http.cpp
index 8642e900..e2322ff7 100644
--- a/blockchain-explorer/blockchain-explorer-http.cpp
+++ b/blockchain-explorer/blockchain-explorer-http.cpp
@@ -35,9 +35,38 @@
 #include "vm/cells/MerkleProof.h"
 #include "block/mc-config.h"
 #include "ton/ton-shard.h"
+#include "td/utils/date.h"
 
 bool local_scripts{false};
 
+static std::string time_to_human(unsigned ts) {
+  td::StringBuilder sb;
+  sb << date::format("%F %T",
+                     std::chrono::time_point<std::chrono::system_clock, std::chrono::seconds>{std::chrono::seconds(ts)})
+     << ", ";
+  auto now = (unsigned)td::Clocks::system();
+  bool past = now >= ts;
+  unsigned x = past ? now - ts : ts - now;
+  if (!past) {
+    sb << "in ";
+  }
+  if (x < 60) {
+    sb << x << "s";
+  } else if (x < 3600) {
+    sb << x / 60 << "m " << x % 60 << "s";
+  } else if (x < 3600 * 24) {
+    x /= 60;
+    sb << x / 60 << "h " << x % 60 << "m";
+  } else {
+    x /= 3600;
+    sb << x / 24 << "d " << x % 24 << "h";
+  }
+  if (past) {
+    sb << " ago";
+  }
+  return sb.as_cslice().str();
+}
+
 HttpAnswer& HttpAnswer::operator<<(AddressCell addr_c) {
   ton::WorkchainId wc;
   ton::StdSmcAddress addr;
@@ -84,7 +113,7 @@ HttpAnswer& HttpAnswer::operator<<(MessageCell msg) {
             << "<tr><th>source</th><td>" << AddressCell{info.src} << "</td></tr>\n"
             << "<tr><th>destination</th><td>NONE</td></tr>\n"
             << "<tr><th>lt</th><td>" << info.created_lt << "</td></tr>\n"
-            << "<tr><th>time</th><td>" << info.created_at << "</td></tr>\n";
+            << "<tr><th>time</th><td>" << info.created_at << " (" << time_to_human(info.created_at) << ")</td></tr>\n";
       break;
     }
     case block::gen::CommonMsgInfo::int_msg_info: {
@@ -103,7 +132,7 @@ HttpAnswer& HttpAnswer::operator<<(MessageCell msg) {
             << "<tr><th>source</th><td>" << AddressCell{info.src} << "</td></tr>\n"
             << "<tr><th>destination</th><td>" << AddressCell{info.dest} << "</td></tr>\n"
             << "<tr><th>lt</th><td>" << info.created_lt << "</td></tr>\n"
-            << "<tr><th>time</th><td>" << info.created_at << "</td></tr>\n"
+            << "<tr><th>time</th><td>" << info.created_at << " (" << time_to_human(info.created_at) << ")</td></tr>\n"
             << "<tr><th>value</th><td>" << value << "</td></tr>\n";
       break;
     }
@@ -277,7 +306,7 @@ HttpAnswer& HttpAnswer::operator<<(TransactionCell trans_c) {
         << "<tr><th>account</th><td>" << trans_c.addr.rserialize(true) << "</td></tr>"
         << "<tr><th>hash</th><td>" << trans_c.root->get_hash().to_hex() << "</td></tr>\n"
         << "<tr><th>lt</th><td>" << trans.lt << "</td></tr>\n"
-        << "<tr><th>time</th><td>" << trans.now << "</td></tr>\n"
+        << "<tr><th>time</th><td>" << trans.now << " (" << time_to_human(trans.now) << ")</td></tr>\n"
         << "<tr><th>out messages</th><td>";
   vm::Dictionary dict{trans.r1.out_msgs, 15};
   for (td::int32 i = 0; i < trans.outmsg_cnt; i++) {
@@ -456,7 +485,7 @@ HttpAnswer& HttpAnswer::operator<<(BlockHeaderCell head_c) {
           << "<tr><th>block</th><td>" << block_id.id.to_str() << "</td></tr>\n"
           << "<tr><th>roothash</th><td>" << block_id.root_hash.to_hex() << "</td></tr>\n"
           << "<tr><th>filehash</th><td>" << block_id.file_hash.to_hex() << "</td></tr>\n"
-          << "<tr><th>time</th><td>" << info.gen_utime << "</td></tr>\n"
+          << "<tr><th>time</th><td>" << info.gen_utime << " (" << time_to_human(info.gen_utime) << ")</td></tr>\n"
           << "<tr><th>lt</th><td>" << info.start_lt << " .. " << info.end_lt << "</td></tr>\n"
           << "<tr><th>global_id</th><td>" << blk.global_id << "</td></tr>\n"
           << "<tr><th>version</th><td>" << info.version << "</td></tr>\n"
@@ -543,7 +572,8 @@ HttpAnswer& HttpAnswer::operator<<(BlockShardsCell shards_c) {
       ton::ShardIdFull shard{id.workchain, id.shard};
       if (ref.not_null()) {
         *this << "<td>" << shard.to_str() << "</td><td><a href=\"" << HttpAnswer::BlockLink{ref->top_block_id()}
-              << "\">" << ref->top_block_id().id.seqno << "</a></td><td>" << ref->created_at() << "</td>"
+              << "\">" << ref->top_block_id().id.seqno << "</a></td><td><span title=\""
+              << time_to_human(ref->created_at()) << "\">" << ref->created_at() << "</span></td>"
               << "<td>" << ref->want_split_ << "</td>"
               << "<td>" << ref->want_merge_ << "</td>"
               << "<td>" << ref->before_split_ << "</td>"
diff --git a/crypto/block/transaction.cpp b/crypto/block/transaction.cpp
index 92a5bfe2..0c77317f 100644
--- a/crypto/block/transaction.cpp
+++ b/crypto/block/transaction.cpp
@@ -962,7 +962,12 @@ int output_actions_count(Ref<vm::Cell> list) {
   int i = -1;
   do {
     ++i;
-    list = load_cell_slice(std::move(list)).prefetch_ref();
+    bool special = true;
+    auto cs = load_cell_slice_special(std::move(list), special);
+    if (special) {
+      break;
+    }
+    list = cs.prefetch_ref();
   } while (list.not_null());
   return i;
 }
@@ -1079,6 +1084,11 @@ bool Transaction::prepare_compute_phase(const ComputePhaseConfig& cfg) {
   } else if (in_msg_state.not_null()) {
     unpack_msg_state(true);  // use only libraries
   }
+  if (in_msg_extern && in_msg_state.not_null() && account.addr != in_msg_state->get_hash().bits()) {
+    LOG(DEBUG) << "in_msg_state hash mismatch in external message";
+    cp.skip_reason = ComputePhase::sk_bad_state;
+    return true;
+  }
   // initialize VM
   Ref<vm::Stack> stack = prepare_vm_stack(cp);
   if (stack.is_null()) {
@@ -1148,7 +1158,8 @@ bool Transaction::prepare_compute_phase(const ComputePhaseConfig& cfg) {
     int out_act_num = output_actions_count(cp.actions);
     if (verbosity > 2) {
       std::cerr << "new smart contract data: ";
-      load_cell_slice(cp.new_data).print_rec(std::cerr);
+      bool can_be_special = true;
+      load_cell_slice_special(cp.new_data, can_be_special).print_rec(std::cerr);
       std::cerr << "output actions: ";
       block::gen::OutList{out_act_num}.print_ref(std::cerr, cp.actions);
     }
@@ -1219,7 +1230,15 @@ bool Transaction::prepare_action_phase(const ActionPhaseConfig& cfg) {
   int n = 0;
   while (true) {
     ap.action_list.push_back(list);
-    auto cs = load_cell_slice(std::move(list));
+    bool special = true;
+    auto cs = load_cell_slice_special(std::move(list), special);
+    if (special) {
+      ap.result_code = 32;  // action list invalid
+      ap.result_arg = n;
+      ap.action_list_invalid = true;
+      LOG(DEBUG) << "action list invalid: special cell";
+      return true;
+    }
     if (!cs.size_ext()) {
       break;
     }
diff --git a/overlay/overlay.cpp b/overlay/overlay.cpp
index 88518eb7..ced7efea 100644
--- a/overlay/overlay.cpp
+++ b/overlay/overlay.cpp
@@ -287,7 +287,11 @@ void OverlayImpl::alarm() {
       if (peers_.size() > 0) {
         std::vector<OverlayNode> vec;
         for (td::uint32 i = 0; i < 20; i++) {
-          vec.push_back(get_random_peer()->get());
+          auto P = get_random_peer();
+          if (!P) {
+            break;
+          }
+          vec.push_back(P->get());
         }
         td::actor::send_closure(manager_, &OverlayManager::save_to_db, local_id_, overlay_id_, std::move(vec));
       }
diff --git a/validator/impl/validate-query.cpp b/validator/impl/validate-query.cpp
index 49885a5f..7ae4bbff 100644
--- a/validator/impl/validate-query.cpp
+++ b/validator/impl/validate-query.cpp
@@ -4904,27 +4904,27 @@ bool ValidateQuery::check_one_library_update(td::ConstBitPtr key, Ref<vm::CellSl
   // shared_lib_descr$00 lib:^Cell publishers:(Hashmap 256 True) = LibDescr;
   std::unique_ptr<vm::Dictionary> old_publishers, new_publishers;
   if (new_value.not_null()) {
-    if (!block::gen::t_LibDescr.validate_csr(new_value)) {
-      return reject_query("LibDescr with key "s + key.to_hex(256) +
-                          " in the libraries dictionary of the new state failed to pass automatic validity tests");
+    block::gen::LibDescr::Record rec;
+    if (!block::gen::csr_unpack(std::move(new_value), rec)) {
+      return reject_query("failed to unpack LibDescr with key "s + key.to_hex(256) +
+                          " in the libraries dictionary of the new state");
     }
-    auto lib_ref = new_value->prefetch_ref();
-    CHECK(lib_ref.not_null());
-    if (lib_ref->get_hash().as_bitslice() != key) {
+    if (rec.lib->get_hash().as_bitslice() != key) {
       return reject_query("LibDescr with key "s + key.to_hex(256) +
                           " in the libraries dictionary of the new state contains a library with different root hash " +
-                          lib_ref->get_hash().to_hex());
+                          rec.lib->get_hash().to_hex());
     }
-    CHECK(new_value.write().advance_ext(2, 1));
-    new_publishers = std::make_unique<vm::Dictionary>(vm::DictNonEmpty(), std::move(new_value), 256);
+    new_publishers = std::make_unique<vm::Dictionary>(vm::DictNonEmpty(), std::move(rec.publishers), 256);
   } else {
     new_publishers = std::make_unique<vm::Dictionary>(256);
   }
-  if (old_value.not_null() && !block::gen::t_LibDescr.validate_csr(old_value)) {
-    return reject_query("LibDescr with key "s + key.to_hex(256) +
-                        " in the libraries dictionary of the old state failed to pass automatic validity tests");
-    CHECK(old_value.write().advance_ext(2, 1));
-    old_publishers = std::make_unique<vm::Dictionary>(vm::DictNonEmpty(), std::move(old_value), 256);
+  if (old_value.not_null()) {
+    block::gen::LibDescr::Record rec;
+    if (!block::gen::csr_unpack(std::move(old_value), rec)) {
+      return reject_query("failed to unpack LibDescr with key "s + key.to_hex(256) +
+                          " in the libraries dictionary of the old state");
+    }
+    old_publishers = std::make_unique<vm::Dictionary>(vm::DictNonEmpty(), std::move(rec.publishers), 256);
   } else {
     old_publishers = std::make_unique<vm::Dictionary>(256);
   }