diff --git a/plugins/omemo/src/logic/manager.vala b/plugins/omemo/src/logic/manager.vala
index 98280a8b..4bb85d59 100644
--- a/plugins/omemo/src/logic/manager.vala
+++ b/plugins/omemo/src/logic/manager.vala
@@ -27,12 +27,11 @@ public class Manager : StreamInteractionModule, Object {
         public bool active_send_attempt { get; set; }
 
         public MessageState(Entities.Message msg, EncryptState last_try) {
-            this.msg = msg;
-            this.last_try = last_try;
-            update_from_encrypt_status(last_try);
+            update_from_encrypt_status(msg, last_try);
         }
 
-        public void update_from_encrypt_status(EncryptState new_try) {
+        public void update_from_encrypt_status(Entities.Message msg, EncryptState new_try) {
+            this.msg = msg;
             this.last_try = new_try;
             this.waiting_other_sessions = new_try.other_unknown;
             this.waiting_own_sessions = new_try.own_unknown;
@@ -56,7 +55,7 @@ public class Manager : StreamInteractionModule, Object {
         }
 
         public string to_string() {
-            return @"MessageState (waiting=(others=$waiting_other_sessions, own=$waiting_own_sessions, other_lists=$waiting_other_devicelists, own_list=$waiting_own_devicelist))";
+            return @"MessageState (msg=$(msg.stanza_id), send=$will_send_now, $last_try)";
         }
     }
 
@@ -127,7 +126,10 @@ public class Manager : StreamInteractionModule, Object {
             lock (message_states) {
                 if (message_states.has_key(message)) {
                     state = message_states.get(message);
-                    state.update_from_encrypt_status(enc_state);
+                    state.update_from_encrypt_status(message, enc_state);
+                    if (state.will_send_now) {
+                        debug("sending message delayed: %s", state.to_string());
+                    }
                 } else {
                     state = new MessageState(message, enc_state);
                     message_states[message] = state;
@@ -140,10 +142,10 @@ public class Manager : StreamInteractionModule, Object {
             //Encryption failed - need to fetch more information
             if (!state.will_send_now) {
                 if (message.marked == Entities.Message.Marked.WONTSEND) {
-                    debug("message was not sent: %s", state.to_string());
+                    debug("retracting message %s", state.to_string());
                     message_states.unset(message);
                 } else {
-                    debug("message will be delayed: %s", state.to_string());
+                    debug("delaying message %s", state.to_string());
 
                     if (state.waiting_own_sessions > 0) {
                         module.fetch_bundles((!)stream, conversation.account.bare_jid, trust_manager.get_trusted_devices(conversation.account, conversation.account.bare_jid));
diff --git a/plugins/omemo/src/logic/trust_manager.vala b/plugins/omemo/src/logic/trust_manager.vala
index 5a169a82..14f19102 100644
--- a/plugins/omemo/src/logic/trust_manager.vala
+++ b/plugins/omemo/src/logic/trust_manager.vala
@@ -175,6 +175,8 @@ public class TrustManager {
             status.encrypted = true;
         } catch (Error e) {
             warning(@"Signal error while encrypting message: $(e.message)\n");
+            message.body = "[OMEMO encryption failed]";
+            status.encrypted = false;
         }
         return status;
     }
diff --git a/plugins/signal-protocol/src/signal_helper.c b/plugins/signal-protocol/src/signal_helper.c
index a9a96a76..74019410 100644
--- a/plugins/signal-protocol/src/signal_helper.c
+++ b/plugins/signal-protocol/src/signal_helper.c
@@ -208,14 +208,14 @@ int signal_vala_encrypt(signal_buffer **output,
         const uint8_t *iv, size_t iv_len,
         const uint8_t *plaintext, size_t plaintext_len,
         void *user_data) {
-    int algo, mode;
-    if (aes_cipher(cipher, key_len, &algo, &mode)) return SG_ERR_UNKNOWN;
+    int algo, mode, error_code = SG_ERR_UNKNOWN;
+    if (aes_cipher(cipher, key_len, &algo, &mode)) return SG_ERR_INVAL;
 
-    if (iv_len != 16 && iv_len != 12) return SG_ERR_UNKNOWN;
+    if (iv_len != 16 && iv_len != 12) return SG_ERR_INVAL;
 
     gcry_cipher_hd_t ctx = {0};
 
-    if (gcry_cipher_open(&ctx, algo, mode, 0)) return SG_ERR_UNKNOWN;
+    if (gcry_cipher_open(&ctx, algo, mode, 0)) return SG_ERR_NOMEM;
 
     signal_buffer* padded = 0;
     signal_buffer* out_buf = 0;
@@ -228,7 +228,7 @@ error:
     if (out_buf != 0) {
         signal_buffer_free(out_buf);
     }
-    return SG_ERR_UNKNOWN;
+    return error_code;
 no_error:
 
     if (gcry_cipher_setkey(ctx, key, key_len)) goto error;
@@ -254,6 +254,7 @@ no_error:
     size_t padded_len = plaintext_len + pad_len;
     padded = signal_buffer_alloc(padded_len);
     if (padded == 0) {
+        error_code = SG_ERR_NOMEM;
         goto error;
     }
 
@@ -262,6 +263,7 @@ no_error:
 
     out_buf = signal_buffer_alloc(padded_len + tag_len);
     if (out_buf == 0) {
+        error_code = SG_ERR_NOMEM;
         goto error;
     }
 
@@ -287,16 +289,16 @@ int signal_vala_decrypt(signal_buffer **output,
         const uint8_t *iv, size_t iv_len,
         const uint8_t *ciphertext, size_t ciphertext_len,
         void *user_data) {
-    int algo, mode;
+    int algo, mode, error_code = SG_ERR_UNKNOWN;
     *output = 0;
-    if (aes_cipher(cipher, key_len, &algo, &mode)) return SG_ERR_UNKNOWN;
-    if (ciphertext_len == 0) return SG_ERR_UNKNOWN;
+    if (aes_cipher(cipher, key_len, &algo, &mode)) return SG_ERR_INVAL;
+    if (ciphertext_len == 0) return SG_ERR_INVAL;
 
-    if (iv_len != 16 && iv_len != 12) return SG_ERR_UNKNOWN;
+    if (iv_len != 16 && iv_len != 12) return SG_ERR_INVAL;
 
     gcry_cipher_hd_t ctx = {0};
 
-    if (gcry_cipher_open(&ctx, algo, mode, 0)) return SG_ERR_UNKNOWN;
+    if (gcry_cipher_open(&ctx, algo, mode, 0)) return SG_ERR_NOMEM;
 
     signal_buffer* out_buf = 0;
     goto no_error;
@@ -305,7 +307,7 @@ error:
     if (out_buf != 0) {
         signal_buffer_bzero_free(out_buf);
     }
-    return SG_ERR_UNKNOWN;
+    return error_code;
 no_error:
 
     if (gcry_cipher_setkey(ctx, key, key_len)) goto error;
@@ -331,6 +333,7 @@ no_error:
     size_t padded_len = ciphertext_len - tag_len;
     out_buf = signal_buffer_alloc(padded_len);
     if (out_buf == 0) {
+        error_code = SG_ERR_NOMEM;
         goto error;
     }