diff --git a/src/cutecoin/core/community.py b/src/cutecoin/core/community.py
index 089a23bfb8b8fc62f7ad7776834bcbaae2320499..5c4ad26dc724d23db34486a58f4d00ae645c9ff3 100644
--- a/src/cutecoin/core/community.py
+++ b/src/cutecoin/core/community.py
@@ -165,7 +165,10 @@ class Community(QObject):
         """
         blocks = self.bma_access.get(self, qtbma.blockchain.UD)['result']['blocks']
         if len(blocks) > 0:
-            block_number = blocks[len(blocks)-(1+x)]
+            index = len(blocks)-(1+x)
+            if index < 0:
+                index = 0
+            block_number = blocks[index]
             block = self.bma_access.get(self, qtbma.blockchain.Block,
                                  req_args={'number': block_number})
             return block
diff --git a/src/cutecoin/gui/informations_tab.py b/src/cutecoin/gui/informations_tab.py
index efe63126feb738457d628de72a1f5d4338c294ff..6b570531220e7d89c127a9bd9d68600e5b1f1a40 100644
--- a/src/cutecoin/gui/informations_tab.py
+++ b/src/cutecoin/gui/informations_tab.py
@@ -150,7 +150,7 @@ class InformationsTabWidget(QWidget, Ui_InformationsTabWidget):
                     localized_mass_minus_1_per_member,
                     self.tr('Monetary Mass per member M(t-1)/N(t) in'),
                     self.get_referential_diff_name(),
-                    float(0) if block_ud['membersCount'] == 0 else
+                    float(0) if block_ud['membersCount'] == 0 or block_ud_minus_1['monetaryMass'] == 0 else
                     block_ud['dividend'] / (block_ud_minus_1['monetaryMass'] / block_ud['membersCount']),
 
                     params['dt'] / 86400,