PHP Deprecated

unserialize(): Passing null to parameter #1 ($data) of type string is deprecated

app/functions/fn.products.php, line: 2861

File:	app/functions/fn.products.php
Line:	2861
Function:	{closure}
File:	app/addons/ab__stickers/func.php
Line:	268
Function:	fn_get_products_layout
File:	app/addons/ab__stickers/functions/fn.hooks.php
Line:	100
Function:	fn_ab__stickers_get_category_page_layout_template
File:	app/functions/fn.control.php
Line:	123
Function:	fn_ab__stickers_gather_additional_products_data_post
File:	app/functions/fn.products.php
Line:	882
Function:	fn_set_hook
File:	app/controllers/frontend/categories.php
Line:	121
Function:	fn_gather_additional_products_data
File:	app/functions/fn.control.php
Line:	728
Function:	include
File:	app/functions/fn.control.php
Line:	459
Function:	fn_run_controller
File:	index.php
Line:	19
Function:	fn_dispatch