diff --git a/htdocs/hrm/class/position.class.php b/htdocs/hrm/class/position.class.php
index 26298c31aa7..bd31311f4bf 100644
--- a/htdocs/hrm/class/position.class.php
+++ b/htdocs/hrm/class/position.class.php
@@ -109,7 +109,7 @@ class Position extends CommonObject
 		'date_creation' => array('type'=>'datetime', 'label'=>'DateCreation', 'enabled'=>'1', 'position'=>500, 'notnull'=>1, 'visible'=>-2,),
 		'tms' => array('type'=>'timestamp', 'label'=>'DateModification', 'enabled'=>'1', 'position'=>501, 'notnull'=>0, 'visible'=>-2,),
 		'fk_contrat' => array('type'=>'integer:Contrat:contrat/class/contrat.class.php', 'label'=>'fk_contrat', 'enabled'=>'1', 'position'=>50, 'notnull'=>0, 'visible'=>0,),
-		'fk_user' => array('type'=>'integer:User:user/class/user.class.php', 'label'=>'Employee', 'enabled'=>'1', 'position'=>55, 'notnull'=>1, 'visible'=>1,),
+		'fk_user' => array('type'=>'integer:User:user/class/user.class.php', 'label'=>'Employee', 'enabled'=>'1', 'position'=>55, 'notnull'=>0, 'visible'=>1,),
 		'fk_job' => array('type'=>'integer:Job:/hrm/class/job.class.php', 'label'=>'Job', 'enabled'=>'1', 'position'=>56, 'notnull'=>1, 'visible'=>1,),
 		'date_start' => array('type'=>'date', 'label'=>'DateStart', 'enabled'=>'1', 'position'=>51, 'notnull'=>1, 'visible'=>1,),
 		'date_end' => array('type'=>'date', 'label'=>'DateEnd', 'enabled'=>'1', 'position'=>52, 'notnull'=>0, 'visible'=>1,),
diff --git a/htdocs/hrm/skill_card.php b/htdocs/hrm/skill_card.php
index 6fa601249db..a06cf40952a 100644
--- a/htdocs/hrm/skill_card.php
+++ b/htdocs/hrm/skill_card.php
@@ -264,7 +264,7 @@ if (($id || $ref) && $action == 'edit') {
 	if (is_array($SkilldetRecords) && count($SkilldetRecords) > 0) {
 		print '<table>';
 		foreach ($SkilldetRecords as $sk) {
-			if ($sk->rank > $MaxNumberSkill) {
+			if ($sk->rankorder > $MaxNumberSkill) {
 				continue;
 			}
 
@@ -291,7 +291,7 @@ if (($id || $ref) && $action == 'edit') {
 				//              if (!empty($val['help'])) {
 				//                  print $form->textwithpicto($langs->trans($val['label']), $langs->trans($val['help']));
 				//              } else {
-					print $langs->trans($val['label']).'&nbsp;'.$langs->trans('rank').'&nbsp;'.$sk->rank;
+					print $langs->trans($val['label']).'&nbsp;'.$langs->trans('rank').'&nbsp;'.$sk->rankorder;
 				//              }
 				print '</td>';
 				print '<td class="valuefieldcreate">';
@@ -696,7 +696,7 @@ if ($action != "create" && $action != "edit") {
 			break; // Should not happen
 		}
 
-		if ($obj->rank > $MaxNumberSkill) {
+		if ($obj->rankorder > $MaxNumberSkill) {
 			continue;
 		}
 
diff --git a/htdocs/install/mysql/migration/14.0.0-15.0.0.sql b/htdocs/install/mysql/migration/14.0.0-15.0.0.sql
index f383c706653..476e63aab68 100644
--- a/htdocs/install/mysql/migration/14.0.0-15.0.0.sql
+++ b/htdocs/install/mysql/migration/14.0.0-15.0.0.sql
@@ -292,7 +292,7 @@ CREATE TABLE llx_hrm_job_user(
     date_creation datetime NOT NULL,
     tms timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     fk_contrat integer,
-    fk_user integer NOT NULL,
+    fk_user integer,
     fk_job integer NOT NULL,
     date_start date,
     date_end date,
diff --git a/htdocs/install/mysql/tables/llx_hrm_job_user-hrm.sql b/htdocs/install/mysql/tables/llx_hrm_job_user-hrm.sql
index 33906d1607f..4e10bf64bf8 100644
--- a/htdocs/install/mysql/tables/llx_hrm_job_user-hrm.sql
+++ b/htdocs/install/mysql/tables/llx_hrm_job_user-hrm.sql
@@ -23,7 +23,7 @@ CREATE TABLE llx_hrm_job_user(
 	date_creation datetime NOT NULL,
 	tms timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 	fk_contrat integer,
-	fk_user integer NOT NULL,
+	fk_user integer,
 	fk_job integer NOT NULL,
 	date_start datetime,
 	date_end datetime,