diff --git a/CHANGELOG b/CHANGELOG
index f2bd7c0..18eaa93 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,10 @@
+2021-04-16
+    - 2.30.1
+    - Fixed an unintialized data member for handling pushed headers.
+    - Added a new status code for version negotiation failure.
+    - Fixed a few compliance issues found by h3spec.
+    - Addressed high CPU usage when transport cannot send pending packets.
+
 2021-04-12
     - 2.30.0
     - Added support for sending/receiving multiple headers to address the
diff --git a/docs/conf.py b/docs/conf.py
index d831549..be6b281 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -26,7 +26,7 @@ author = u'LiteSpeed Technologies'
 # The short X.Y version
 version = u'2.30'
 # The full version, including alpha/beta/rc tags
-release = u'2.30.0'
+release = u'2.30.1'
 
 
 # -- General configuration ---------------------------------------------------
diff --git a/include/lsquic.h b/include/lsquic.h
index 344303c..8f90315 100644
--- a/include/lsquic.h
+++ b/include/lsquic.h
@@ -25,7 +25,7 @@ extern "C" {
 
 #define LSQUIC_MAJOR_VERSION 2
 #define LSQUIC_MINOR_VERSION 30
-#define LSQUIC_PATCH_VERSION 0
+#define LSQUIC_PATCH_VERSION 1
 
 /**
  * Engine flags:
@@ -2088,6 +2088,7 @@ enum LSQUIC_CONN_STATUS
     LSCONN_ST_ERROR,
     LSCONN_ST_CLOSED,
     LSCONN_ST_PEER_GOING_AWAY,
+    LSCONN_ST_VERNEG_FAILURE,
 };
 
 enum LSQUIC_CONN_STATUS
diff --git a/src/liblsquic/lsquic_engine.c b/src/liblsquic/lsquic_engine.c
index 0a11837..be6341d 100644
--- a/src/liblsquic/lsquic_engine.c
+++ b/src/liblsquic/lsquic_engine.c
@@ -3188,7 +3188,8 @@ lsquic_engine_earliest_adv_tick (lsquic_engine_t *engine, int *diff)
         return 1;
     }
 
-    if (engine->pr_queue && lsquic_prq_have_pending(engine->pr_queue))
+    if ((engine->pub.enp_flags & ENPUB_CAN_SEND)
+        && engine->pr_queue && lsquic_prq_have_pending(engine->pr_queue))
     {
 #if LSQUIC_DEBUG_NEXT_ADV_TICK
         engine->last_logged_conn = 0;
diff --git a/src/liblsquic/lsquic_full_conn.c b/src/liblsquic/lsquic_full_conn.c
index 95572bf..b561865 100644
--- a/src/liblsquic/lsquic_full_conn.c
+++ b/src/liblsquic/lsquic_full_conn.c
@@ -2283,6 +2283,7 @@ process_ver_neg_packet (struct full_conn *conn, lsquic_packet_in_t *packet_in)
     versions &= conn->fc_ver_neg.vn_supp;
     if (0 == versions)
     {
+        conn->fc_flags |= FC_HSK_FAILED;
         ABORT_ERROR("client does not support any of the server-specified "
                     "versions");
         return;
@@ -4087,6 +4088,7 @@ synthesize_push_request (struct full_conn *conn, void *hset,
     if (lsquic_http1x_if == conn->fc_enpub->enp_hsi_if)
         uh->uh_flags    |= UH_H1H;
     uh->uh_hset          = hset;
+    uh->uh_next          = NULL;
 
     return uh;
 }
@@ -4230,7 +4232,12 @@ full_conn_ci_status (struct lsquic_conn *lconn, char *errbuf, size_t bufsz)
     }
 
     if (conn->fc_flags & FC_ERROR)
-        return LSCONN_ST_ERROR;
+    {
+        if (conn->fc_flags & FC_HSK_FAILED)
+            return LSCONN_ST_VERNEG_FAILURE;
+        else
+            return LSCONN_ST_ERROR;
+    }
     if (conn->fc_flags & FC_TIMED_OUT)
         return LSCONN_ST_TIMED_OUT;
     if (conn->fc_flags & FC_ABORTED)
diff --git a/src/liblsquic/lsquic_full_conn_ietf.c b/src/liblsquic/lsquic_full_conn_ietf.c
index 4ce0570..b1f9979 100644
--- a/src/liblsquic/lsquic_full_conn_ietf.c
+++ b/src/liblsquic/lsquic_full_conn_ietf.c
@@ -4018,6 +4018,7 @@ ietf_full_conn_ci_push_stream (struct lsquic_conn *lconn, void *hset,
     uh->uh_exclusive     = 0;
     uh->uh_flags         = UH_FIN;
     uh->uh_hset          = hset;
+    uh->uh_next          = NULL;
 
     memset(promise, 0, sizeof(*promise));
     promise->pp_refcnt = 1; /* This function itself keeps a reference */
@@ -7587,7 +7588,7 @@ process_incoming_packet_verneg (struct ietf_full_conn *conn,
          */
         if (!verneg_ok(conn))
         {
-            ABORT_WITH_FLAG(conn, LSQ_LOG_NOTICE, IFC_ERROR,
+            ABORT_WITH_FLAG(conn, LSQ_LOG_NOTICE, IFC_ERROR|IFC_HSK_FAILED,
                 "version negotiation not permitted in this version of QUIC");
             return -1;
         }
@@ -7595,7 +7596,7 @@ process_incoming_packet_verneg (struct ietf_full_conn *conn,
         versions &= conn->ifc_u.cli.ifcli_ver_neg.vn_supp;
         if (0 == versions)
         {
-            ABORT_WITH_FLAG(conn, LSQ_LOG_NOTICE, IFC_ERROR,
+            ABORT_WITH_FLAG(conn, LSQ_LOG_NOTICE, IFC_ERROR|IFC_HSK_FAILED,
                 "client does not support any of the server-specified versions");
             return -1;
         }
@@ -8461,7 +8462,12 @@ ietf_full_conn_ci_status (struct lsquic_conn *lconn, char *errbuf, size_t bufsz)
     }
 
     if (conn->ifc_flags & IFC_ERROR)
-        return LSCONN_ST_ERROR;
+    {
+        if (conn->ifc_flags & IFC_HSK_FAILED)
+            return LSCONN_ST_VERNEG_FAILURE;
+        else
+            return LSCONN_ST_ERROR;
+    }
     if (conn->ifc_flags & IFC_TIMED_OUT)
         return LSCONN_ST_TIMED_OUT;
     if (conn->ifc_flags & IFC_ABORTED)
@@ -8564,6 +8570,8 @@ ietf_full_conn_ci_abort_error (struct lsquic_conn *lconn, int is_app,
     const char *err_str, *percent;
     char err_buf[0x100];
 
+    if (conn->ifc_error.u.err != 0)
+        return;
     percent = strchr(fmt, '%');
     if (percent)
     {
@@ -9344,11 +9352,15 @@ on_priority_update_server (void *ctx, enum hq_frame_type frame_type,
 
 
 static void
-on_unexpected_frame (void *ctx, uint64_t frame_type)
+on_frame_error (void *ctx, unsigned code, uint64_t frame_type)
 {
     struct ietf_full_conn *const conn = ctx;
-    ABORT_QUIETLY(1, HEC_FRAME_UNEXPECTED, "Frame type %"PRIu64" is not "
-        "allowed on the control stream", frame_type);
+    if (code == HEC_MISSING_SETTINGS)
+        ABORT_QUIETLY(1, code, "The first control frame is not SETTINGS, "
+                     "got frame type %"PRIu64, frame_type);
+    else
+        ABORT_QUIETLY(1, HEC_FRAME_UNEXPECTED, "Frame type %"PRIu64" is not "
+            "allowed on the control stream", frame_type);
 }
 
 
@@ -9359,7 +9371,7 @@ static const struct hcsi_callbacks hcsi_callbacks_server_27 =
     .on_settings_frame      = on_settings_frame,
     .on_setting             = on_setting,
     .on_goaway              = on_goaway_server_27,
-    .on_unexpected_frame    = on_unexpected_frame,
+    .on_frame_error         = on_frame_error,
     .on_priority_update     = on_priority_update_server,
 };
 
@@ -9370,7 +9382,7 @@ static const struct hcsi_callbacks hcsi_callbacks_client_27 =
     .on_settings_frame      = on_settings_frame,
     .on_setting             = on_setting,
     .on_goaway              = on_goaway_client_27,
-    .on_unexpected_frame    = on_unexpected_frame,
+    .on_frame_error         = on_frame_error,
     .on_priority_update     = on_priority_update_client,
 };
 
@@ -9382,7 +9394,7 @@ static const struct hcsi_callbacks hcsi_callbacks_server_29 =
     .on_settings_frame      = on_settings_frame,
     .on_setting             = on_setting,
     .on_goaway              = on_goaway_server,
-    .on_unexpected_frame    = on_unexpected_frame,
+    .on_frame_error         = on_frame_error,
     .on_priority_update     = on_priority_update_server,
 };
 
@@ -9393,7 +9405,7 @@ static const struct hcsi_callbacks hcsi_callbacks_client_29 =
     .on_settings_frame      = on_settings_frame,
     .on_setting             = on_setting,
     .on_goaway              = on_goaway_client,
-    .on_unexpected_frame    = on_unexpected_frame,
+    .on_frame_error         = on_frame_error,
     .on_priority_update     = on_priority_update_client,
 };
 
diff --git a/src/liblsquic/lsquic_hcsi_reader.c b/src/liblsquic/lsquic_hcsi_reader.c
index 671ef2c..8b365b6 100644
--- a/src/liblsquic/lsquic_hcsi_reader.c
+++ b/src/liblsquic/lsquic_hcsi_reader.c
@@ -61,9 +61,19 @@ lsquic_hcsi_reader_feed (struct hcsi_reader *reader, const void *buf,
                 break;
             reader->hr_frame_type = reader->hr_u.vint2_state.vr2s_one;
             reader->hr_frame_length = reader->hr_u.vint2_state.vr2s_two;
+
+            if (!(reader->hr_flag & HR_FLAG_RCVD_SETTING)
+                && reader->hr_frame_type != HQFT_SETTINGS)
+            {
+                reader->hr_cb->on_frame_error(reader->hr_ctx,
+                            HEC_MISSING_SETTINGS, reader->hr_frame_type);
+                return -1;
+            }
+
             switch (reader->hr_frame_type)
             {
             case HQFT_SETTINGS:
+                reader->hr_flag |= HR_FLAG_RCVD_SETTING;
                 if (reader->hr_frame_length)
                 {
                     reader->hr_state = HR_READ_SETTING_BEGIN;
@@ -91,8 +101,8 @@ lsquic_hcsi_reader_feed (struct hcsi_reader *reader, const void *buf,
             case HQFT_DATA:
             case HQFT_HEADERS:
             case HQFT_PUSH_PROMISE:
-                reader->hr_cb->on_unexpected_frame(reader->hr_ctx,
-                                                        reader->hr_frame_type);
+                reader->hr_cb->on_frame_error(reader->hr_ctx,
+                    HEC_FRAME_UNEXPECTED, reader->hr_frame_type);
                 return -1;
             default:
             {
diff --git a/src/liblsquic/lsquic_hcsi_reader.h b/src/liblsquic/lsquic_hcsi_reader.h
index 44360eb..75a91ea 100644
--- a/src/liblsquic/lsquic_hcsi_reader.h
+++ b/src/liblsquic/lsquic_hcsi_reader.h
@@ -17,7 +17,7 @@ struct hcsi_callbacks
     void    (*on_settings_frame)(void *ctx);
     void    (*on_setting)(void *ctx, uint64_t setting_id, uint64_t value);
     void    (*on_goaway)(void *ctx, uint64_t stream_id);
-    void    (*on_unexpected_frame)(void *ctx, uint64_t frame_type);
+    void    (*on_frame_error)(void *ctx, unsigned code, uint64_t frame_type);
     void    (*on_priority_update)(void *ctx, enum hq_frame_type, uint64_t id,
                                                         const char *, size_t);
 };
@@ -35,7 +35,11 @@ struct hcsi_reader
         HR_READ_VARINT,
         HR_READ_VARINT_CONTINUE,
         HR_ERROR,
-    }                               hr_state;
+    }                               hr_state:8;
+    enum {
+        HR_FLAG_RCVD_SETTING = 1,
+    }                               hr_flag:8;
+    unsigned                        hr_nread;  /* Used for PRIORITY_UPDATE and SETTINGS frames */
     struct lsquic_conn             *hr_conn;
     uint64_t                        hr_frame_type;
     uint64_t                        hr_frame_length;
@@ -55,7 +59,6 @@ struct hcsi_reader
     }                               hr_u;
     const struct hcsi_callbacks    *hr_cb;
     void                           *hr_ctx;
-    unsigned                        hr_nread;  /* Used for PRIORITY_UPDATE and SETTINGS frames */
 };
 
 
diff --git a/src/liblsquic/lsquic_qdec_hdl.c b/src/liblsquic/lsquic_qdec_hdl.c
index 062a9cf..e8c50de 100644
--- a/src/liblsquic/lsquic_qdec_hdl.c
+++ b/src/liblsquic/lsquic_qdec_hdl.c
@@ -565,7 +565,7 @@ qdh_hsi_process_wrapper (struct qpack_dec_hdl *qdh, void *hset,
     retval = qdh->qdh_enpub->enp_hsi_if->hsi_process_header(hset, xhdr);
     if (0 != retval)
         qdh->qdh_conn->cn_if->ci_abort_error(qdh->qdh_conn, 1,
-            1 == retval ? HEC_MESSAGE_ERROR : HEC_INTERNAL_ERROR,
+            HEC_MESSAGE_ERROR,
             "error processing headers");
 
     return retval;
diff --git a/tests/test_hcsi_reader.c b/tests/test_hcsi_reader.c
index 0e802ea..74432c8 100644
--- a/tests/test_hcsi_reader.c
+++ b/tests/test_hcsi_reader.c
@@ -189,7 +189,7 @@ on_goaway (void *ctx, uint64_t stream_id)
 }
 
 static void
-on_unexpected_frame (void *ctx, uint64_t frame_type)
+on_frame_error (void *ctx, unsigned code, uint64_t frame_type)
 {
     fprintf(ctx, "%s: %"PRIu64"\n", __func__, frame_type);
 }
@@ -219,7 +219,7 @@ static const struct hcsi_callbacks callbacks =
     .on_settings_frame      = on_settings_frame,
     .on_setting             = on_setting,
     .on_goaway              = on_goaway,
-    .on_unexpected_frame    = on_unexpected_frame,
+    .on_frame_error         = on_frame_error,
     .on_priority_update     = on_priority_update,
 };
 
@@ -252,6 +252,7 @@ run_test (const struct test *test)
     {
         out_f = open_memstream(&output, &out_sz);
         lsquic_hcsi_reader_init(&reader, &lconn, &callbacks, out_f);
+        reader.hr_flag |= HR_FLAG_RCVD_SETTING;
 
         p = test->input;
         do