diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 0aca6a94213..db593f8d76a 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -5962,7 +5962,7 @@ class Form
 	 * @param	int				$forcecombo			Force to load all values and output a standard combobox (with no beautification)
 	 * @param	int				$outputmode			0=HTML select string, 1=Array
 	 * @param	int				$disabled			1=Html component is disabled
-	 * @return	string								Return HTML string
+	 * @return	string|array						Return HTML string
 	 * @see selectForForms()
 	 */
     public function selectForFormsList($objecttmp, $htmlname, $preselectedvalue, $showempty = '', $searchkey = '', $placeholder = '', $morecss = '', $moreparams = '', $forcecombo = 0, $outputmode = 0, $disabled = 0)
@@ -5975,8 +5975,7 @@ class Form
 		if ($prefixforautocompletemode == 'societe') $prefixforautocompletemode='company';
 		$confkeyforautocompletemode=strtoupper($prefixforautocompletemode).'_USE_SEARCH_TO_SELECT';	// For example COMPANY_USE_SEARCH_TO_SELECT
 
-		$fieldstoshow='t.ref';
-		if (! empty($objecttmp->fields))	// For object that declare it, it is better to use declared fields ( like societe, contact, ...)
+		if (! empty($objecttmp->fields))	// For object that declare it, it is better to use declared fields (like societe, contact, ...)
 		{
 			$tmpfieldstoshow='';
 			foreach($objecttmp->fields as $key => $val)
@@ -5985,6 +5984,18 @@ class Form
 			}
 			if ($tmpfieldstoshow) $fieldstoshow = $tmpfieldstoshow;
 		}
+		if (empty($fieldstoshow))
+		{
+			if (isset($objecttmp->fields['ref'])) {
+				$fieldstoshow='t.ref';
+			}
+			else
+			{
+				$langs->load("errors");
+				$this->error = $langs->trans("ErrorNoFieldWithAttributeShowoncombobox");
+				return $langs->trans('ErrorNoFieldWithAttributeShowoncombobox');
+			}
+		}
 
 		$out='';
 		$outarray=array();
diff --git a/htdocs/langs/en_US/errors.lang b/htdocs/langs/en_US/errors.lang
index 96eedb296a3..2b23fc6d19e 100644
--- a/htdocs/langs/en_US/errors.lang
+++ b/htdocs/langs/en_US/errors.lang
@@ -222,6 +222,7 @@ ErrorDeletePaymentLinkedToAClosedInvoiceNotPossible=Error, delete payment linked
 ErrorSearchCriteriaTooSmall=Search criteria too small.
 ErrorObjectMustHaveStatusActiveToBeDisabled=Objects must have status 'Active' to be disabled
 ErrorObjectMustHaveStatusDraftOrDisabledToBeActivated=Objects must have status 'Draft' or 'Disabled' to be enabled
+ErrorNoFieldWithAttributeShowoncombobox=No fields has property 'showoncombobox' into definition of object '%s'. No way to show the combolist. 
 # Warnings
 WarningParamUploadMaxFileSizeHigherThanPostMaxSize=Your PHP parameter upload_max_filesize (%s) is higher than PHP parameter post_max_size (%s). This is not a consistent setup.
 WarningPasswordSetWithNoAccount=A password was set for this member. However, no user account was created. So this password is stored but can't be used to login to Dolibarr. It may be used by an external module/interface but if you don't need to define any login nor password for a member, you can disable option "Manage a login for each member" from Member module setup. If you need to manage a login but don't need any password, you can keep this field empty to avoid this warning. Note: Email can also be used as a login if the member is linked to a user.