Index: branches/5.1.x/core/install/upgrades.sql
===================================================================
diff -u -N -r13789 -r13811
--- branches/5.1.x/core/install/upgrades.sql	(.../upgrades.sql)	(revision 13789)
+++ branches/5.1.x/core/install/upgrades.sql	(.../upgrades.sql)	(revision 13811)
@@ -1922,3 +1922,6 @@
 UPDATE ConfigurationValues
 SET DisplayOrder = DisplayOrder - 0.01
 WHERE ModuleOwner = 'In-Portal' AND `Section` = 'in-portal:configure_categories' AND DisplayOrder > 10.07;
+
+# ===== v 5.1.0 =====
+UPDATE Events SET Headers = NULL WHERE Headers = '';