here is the errors log :
2020-08-31 13:20:52 - warning: AbanteCart core v.1.2.16 Use of undefined constant CACHE_DRIVER - assumed 'CACHE_DRIVER' (this will throw an Error in a future version of PHP) in <b>/home/public_html/core/helper/system_check.php</b> on line <b>126</b>
2020-08-31 13:20:57 - warning: AbanteCart core v.1.2.16 mkdir(): File exists in <b>/home/public_html/core/helper/utils.php</b> on line <b>1306</b>
2020-08-31 13:20:57 - App Warning: AbanteCart core v.1.2.16 Cannot to create directory /home/public_html/image//thumbnails/18/8d. Please check permissions for /home/public_html/image/ in /home/public_html/core/helper/utils.php on line 1311
2020-08-31 13:22:03 - warning: AbanteCart core v.1.2.16 Use of undefined constant CACHE_DRIVER - assumed 'CACHE_DRIVER' (this will throw an Error in a future version of PHP) in <b>/home/public_html/core/helper/system_check.php</b> on line <b>126</b>
2020-08-31 13:23:04 - database error: AbanteCart core v.1.2.16 SQL Error: MySQL server has gone away
Error No: 2006
SQL: SELECT p.product_id,
p.subtract,
SUM(COALESCE(pov.subtract,0)) as option_subtract,
p.quantity,
SUM(COALESCE(pov.quantity,0)) as option_quantity
FROM ac_products p
LEFT JOIN ac_product_options po
ON (po.product_id = p.product_id AND po.status = 1)
LEFT JOIN ac_product_option_values pov
ON (po.product_option_id = pov.product_option_id)
WHERE p.product_id IN (935, 936, 937, 938, 939, 934, 932, 933, 923, 924, 925, 926, 927, 928, 929, 930, 909, 910, 911, 912, 913, 914, 891, 882, 883, 884, 879, 880, 881, 860, 861, 862)
GROUP BY p.product_id
PHP call stack:
#0 /home/public_html/core/lib/db.php:100
#1 /home/public_html/core/engine/extensions.php:1176
#2 /home/public_html/core/engine/extensions.php:1127
#3 /home/public_html/core/lib/db.php:67
#4 /home/public_html/storefront/model/catalog/product.php:133
#5 /home/public_html/storefront/controller/blocks/featured.php:63
#6 /home/public_html/core/engine/dispatcher.php:293
#7 /home/public_html/core/engine/dispatcher.php:328
#8 /home/public_html/core/engine/dispatcher.php:328
#9 /home/public_html/core/engine/page.php:108
#10 /home/public_html/core/engine/router.php:176
#11 /home/public_html/core/engine/router.php:80
#12 /home/public_html/index.php:94
in <b>/home/public_html/core/database/amysqli.php</b> on line <b>119</b>
2020-08-31 13:23:30 - warning: AbanteCart core v.1.2.16 Use of undefined constant CACHE_DRIVER - assumed 'CACHE_DRIVER' (this will throw an Error in a future version of PHP) in <b>/home/public_html/core/helper/system_check.php</b> on line <b>126</b>