Critical uncaught exception since WP 5.4 update

Hey,

First, i’d like to thank you for your worK.
I’m building a site with WP & Woo, and using your plugin to display products in widgetss, post & pages.
It was working just fine till this morning. I’ve updated WP to version 5.4, then the website stop working and showing a blank page(but the admin panel still works).

After looking at WP logs, i’ve seen this :

2020-04-06T07:57:48+00:00 CRITICAL Uncaught Error: Cannot use object of type WP_Error as array in /home/user/domains/domain.com/public_html/wp-content/plugins/shortcodes-ultimate/includes/shortcodes/custom-gallery.php:133
Stack trace:
#0 /home/user/domains/domain.com/public_html/wp-includes/shortcodes.php(343): su_shortcode_custom_gallery(Array, ”, ‘su_custom_galle…’)
#1 [internal function]: do_shortcode_tag(Array)
#2 /home/user/domains/domain.com/public_html/wp-includes/shortcodes.php(218): preg_replace_callback(‘/\\[(\\[?)(su_cus…’, ‘do_shortcode_ta…’, ‘[su_custom_gall…’)
#3 /home/user/domains/domain.com/public_html/wp-includes/class-wp-hook.php(289): do_shortcode(‘[su_custom_gall…’)
#4 /home/user/domains/domain.com/public_html/wp-includes/plugin.php(206): WP_Hook->apply_filters(‘[su_custom_gall…’, Array)
#5 /home/user/domains/domain.com/public_html/wp-includes/widgets/class-wp-widget-text.php(295): apply_filters(‘widget_text_con…’, ‘[su_custom_gall…’, Array, Object(WP_Widget_Text))
#6 /home/user/do dans /home/user/domains/domain.com/public_html/wp-content/plugins/shortcodes-ultimate/includes/shortcodes/custom-gallery.php on line 133

Edit : it looks like there is conflict with another plugin, mega main menu. If i disable this plugin and activate shortcode-ultimate, the site shows no more blank page, but the shortcodes doesn’t display any content.

And Shortcode Ultimate & Mega main menu was working fini till WP 5.4 update.

Sorry for the inconvenience,
Best Regards,
Arnaud