Item ID must be a string or integer in .../item-registry.php on line 78
Hello, I have the following problem. When adding the advertisement at the "preview" stage, it calculates the price for the advertisement nicely, I go further to the "basket" and here Total 0 PLN pops up.
WP also throws the following error:
Warning: Item ID must be a string or integer in .../
wp-content/themes/classipress/includes/payments/item-registry.php on line 78 Warning: Item ID must be a string or integer in .../
wp-content/themes/classipress/includes/payments/item-registry.php on line 78 Warning: Item ID must be a string or integer in .../
wp-content/themes/classipress/includes/payments/item-registry.php on line 90 Warning: Item ID must be a string or integer in .../
wp-content/themes/classipress/includes/payments/item-registry.php on line 90
I do not know what it means, please help.