diff --git a/src/ChamiloLMS/Transaction/Envelope.php b/src/ChamiloLMS/Transaction/Envelope.php
index 2564f10c1e..d834f38076 100644
--- a/src/ChamiloLMS/Transaction/Envelope.php
+++ b/src/ChamiloLMS/Transaction/Envelope.php
@@ -160,7 +160,7 @@ class Envelope
      *
      * @return array
      *   An array with the metadata. Contains the following keys:
-     *   - 'type': The wrapper plugin machine name.
+     *   - 'blob_type': The wrapper plugin machine name.
      *   - 'origin_branch_id': The branch where the blob was generated.
      */
     public static function identifyBlobMetadata($blob) {
diff --git a/src/ChamiloLMS/Transaction/Plugin/SslSignedJsonWrapper.php b/src/ChamiloLMS/Transaction/Plugin/SslSignedJsonWrapper.php
index aac5ec472d..b0817aaa24 100644
--- a/src/ChamiloLMS/Transaction/Plugin/SslSignedJsonWrapper.php
+++ b/src/ChamiloLMS/Transaction/Plugin/SslSignedJsonWrapper.php
@@ -192,7 +192,7 @@ class SslSignedJsonWrapper extends JsonWrapper
                 throw new UnwrapException(self::format_log(sprintf('Problem veryfing signer branch: %s.', $exception->getMessage())));
             }
             if (!$declared_branch_is_valid) {
-                $message = sprintf('Declared branch with id "%d" is not the same than real signer branch. Possible attack attempt to inject transactions with other valid branch signature.', $branch->getId());
+                $message = sprintf('Declared branch with id "%d" is not the same than real signer branch. Possible attack attempt to inject transactions with other valid branch signature.', $declared_origin_branch->getId());
                 // Try to identify it.
                 if (!$branch_id = $this->identifySignerBranch($envelope_metadata['origin_branch_id'], $signer_certificates_file)) {
                     $message .= sprintf(' Cannot retrieve any valid branch associated with the signer certificate file "%s". Altered data?', $signer_certificates_file);
diff --git a/src/ChamiloLMS/Transaction/TransactionLogController.php b/src/ChamiloLMS/Transaction/TransactionLogController.php
index 1d20a8d64a..886eb0b6f2 100644
--- a/src/ChamiloLMS/Transaction/TransactionLogController.php
+++ b/src/ChamiloLMS/Transaction/TransactionLogController.php
@@ -172,7 +172,7 @@ class TransactionLogController
      *   An array keyed by received envelope id containing an array transaction
      *   ids added based on that received envelope.
      */
-    public static function importPendingEnvelopes($limit = 0) {
+    public function importPendingEnvelopes($limit = 0) {
         $table = Database::get_main_table(TABLE_RECEIVED_ENVELOPES);
         $log_entry = array('log_type' => self::LOG_IMPORT_TO_TX_QUEUE);
         // Sadly limit clause is not supported by Database::select().
@@ -188,8 +188,8 @@ class TransactionLogController
             try {
                 $blob_metadata = Envelope::identifyBlobMetadata($row['data']);
                 $origin_branch = $this->branchRepository->find($blob_metadata['origin_branch_id']);
-                $wrapper_plugin = self::createPlugin('wrapper', $blob_metadata['type'], $origin_branch->getPluginData('wrapper'));
-                $envelope_data = array('blob' => $blob, 'origin_branch_id' => $blob_metadata['origin_branch_id']);
+                $wrapper_plugin = self::createPlugin('wrapper', $blob_metadata['blob_type'], $origin_branch->getPluginData('wrapper'));
+                $envelope_data = array('blob' => $row['data'], 'origin_branch_id' => $blob_metadata['origin_branch_id']);
                 $envelope = new Envelope($wrapper_plugin, $envelope_data);
                 $envelope->unwrap();
                 $transactions = $envelope->getTransactions();
@@ -567,7 +567,10 @@ class TransactionLogController
             try {
                 $blob_metadata = Envelope::identifyBlobMetadata($blob);
                 $origin_branch = $this->branchRepository->find($blob_metadata['origin_branch_id']);
-                $wrapper_plugin = self::createPlugin('wrapper', $blob_metadata['type'], $origin_branch->getPluginData('wrapper'));
+                if (!$origin_branch) {
+                    throw new Exception(sprintf('Cannot find a local branch with id %s', $blob_metadata['origin_branch_id']));
+                }
+                $wrapper_plugin = self::createPlugin('wrapper', $blob_metadata['blob_type'], $origin_branch->getPluginData('wrapper'));
                 $envelope_data = array('blob' => $blob, 'origin_branch_id' => $blob_metadata['origin_branch_id']);
                 $envelope = new Envelope($wrapper_plugin, $envelope_data);
             }