diff --git a/htdocs/api/class/api.class.php b/htdocs/api/class/api.class.php
index 664b054ebc5..3c66369028a 100644
--- a/htdocs/api/class/api.class.php
+++ b/htdocs/api/class/api.class.php
@@ -59,6 +59,18 @@ class DolibarrApi
 
 		$this->db = $db;
 		$production_mode = (empty($conf->global->API_PRODUCTION_MODE) ? false : true);
+
+		if ($production_mode) {
+			// Create the directory Defaults::$cacheDirectory if it does not exist. If dir does not exist, using production_mode generates an error 500.
+			include_once DOL_DOCUMENT_ROOT.'/core/lib/files.lib.php';
+			if (!dol_is_dir(Defaults::$cacheDirectory)) {
+				dol_mkdir(Defaults::$cacheDirectory, DOL_DATA_ROOT);
+			}
+			if (getDolGlobalString('MAIN_API_DEBUG')) {
+				dol_syslog("Debug API construct::cacheDirectory=".Defaults::$cacheDirectory, LOG_DEBUG, 0, '_api');
+			}
+		}
+
 		$this->r = new Restler($production_mode, $refreshCache);
 
 		$urlwithouturlroot = preg_replace('/'.preg_quote(DOL_URL_ROOT, '/').'$/i', '', trim($dolibarr_main_url_root));
diff --git a/htdocs/product/stats/bom.php b/htdocs/product/stats/bom.php
index 851bf118823..c9a1fb2f04c 100644
--- a/htdocs/product/stats/bom.php
+++ b/htdocs/product/stats/bom.php
@@ -230,7 +230,7 @@ if ($id > 0 || !empty($ref)) {
 					$bomtmp->ref = $objp->ref;
 					$product = new Product($db);
 					if (!empty($objp->fk_product)) {
-						if (!array_key_exists($product->id, $product_cache)) {
+						if (!array_key_exists($objp->fk_product, $product_cache)) {
 							$resultFetch = $product->fetch($objp->fk_product);
 							if ($resultFetch < 0) {
 								setEventMessages($product->error, $product->errors, 'errors');