diff --git a/htdocs/install/mysql/migration/12.0.0-13.0.0.sql b/htdocs/install/mysql/migration/12.0.0-13.0.0.sql
index 33b8ea01f8b..b042fea292d 100644
--- a/htdocs/install/mysql/migration/12.0.0-13.0.0.sql
+++ b/htdocs/install/mysql/migration/12.0.0-13.0.0.sql
@@ -366,6 +366,8 @@ ALTER TABLE llx_facturedet ADD COLUMN ref_ext varchar(255) AFTER multicurrency_t
 ALTER TABLE llx_c_ticket_category ADD COLUMN fk_parent integer DEFAULT 0 NOT NULL;
 ALTER TABLE llx_c_ticket_category ADD COLUMN force_severity varchar(32) NULL;
 
+ALTER TABLE llx_c_ticket_severity CHANGE color color VARCHAR(10) NULL; 
+
 ALTER TABLE llx_expensereport ADD COLUMN fk_user_creat integer NULL;
 
 ALTER TABLE llx_expensereport_ik ADD COLUMN ikoffset double DEFAULT 0 NOT NULL;
diff --git a/htdocs/install/mysql/tables/llx_c_ticket_severity.sql b/htdocs/install/mysql/tables/llx_c_ticket_severity.sql
index bb8a75abaa9..b9f565c4395 100644
--- a/htdocs/install/mysql/tables/llx_c_ticket_severity.sql
+++ b/htdocs/install/mysql/tables/llx_c_ticket_severity.sql
@@ -22,7 +22,7 @@ create table llx_c_ticket_severity
   code			varchar(32)				NOT NULL,
   pos			varchar(32)				NOT NULL,
   label			varchar(128)			NOT NULL,
-  color			varchar(10)				NOT NULL,
+  color			varchar(10)				NULL,
   active		integer DEFAULT 1,
   use_default	integer DEFAULT 1,
   description	varchar(255)
diff --git a/htdocs/ticket/index.php b/htdocs/ticket/index.php
index ed304c43976..52e10f78454 100644
--- a/htdocs/ticket/index.php
+++ b/htdocs/ticket/index.php
@@ -387,7 +387,7 @@ if ($result) {
 			$i++;
 		}
 
-		$db->free();
+		$db->free($result);
 	} else {
 		print '<tr><td colspan="6" class="opacitymedium">'.$langs->trans('NoUnreadTicketsFound').'</td></tr>';
 	}