Bug when I add a new product

Hi,

When i add a new product in WPshop there are this error :
WPshop ver. : 1.6.0
Wordpress ver. : 4.9.7 fr
Wamp ver. : 3.1.3
PhP ver. : 7.2.4
MySQL ver. : 5.7.21

( ! ) Fatal error: Uncaught Error: Cannot use string offset as an array in E:\Wamp64\www\wp-content\plugins\wpshop\includes\librairies\eav\attributes_set.class.php on line 977
( ! ) Error: Cannot use string offset as an array in E:\Wamp64\www\wp-content\plugins\wpshop\includes\librairies\eav\attributes_set.class.php on line 977
Call Stack
# Time Memory Function Location
1 0.0002 410064 {main}( ) …\post-new.php:0
2 1.0687 23535952 include( ‘E:\Wamp64\www\wp-admin\edit-form-advanced.php’ ) …\post-new.php:76
3 1.0772 23568192 do_action( ) …\edit-form-advanced.php:334
4 1.0772 23568568 WP_Hook->do_action( ) …\plugin.php:453
5 1.0772 23568568 WP_Hook->apply_filters( ) …\class-wp-hook.php:310
6 1.0788 23592936 wpshop_products::add_meta_boxes( ) …\class-wp-hook.php:288
7 1.0841 23595080 wpshop_attributes::entities_attribute_box( ) …\products.class.php:250
8 1.0841 23595456 wpshop_attributes_set::getAttributeSetDetails( ) …\attributes.class.php:2243