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[21-May-2021 10:18:35 UTC] PHP Notice: Undefined offset: -1 in /home/ABC/public_html/wp-content/plugins/wp-fastest-cache/inc/js-utilities.php on line 48

My debug.log is full with messages please check

### wp-core ###

version: 5.5.3
site_language: en_GB
user_language: en_GB
timezone: +00:00
permalink: /%postname%/
https_status: true
multisite: false
user_registration: 1
blog_public: 1
default_comment_status: closed
environment_type: production
user_count: 54643
dotorg_communication: true

### wp-paths-sizes ###

### wp-active-theme ###

name: Flatsome Child (flatsome-child)
version: 3.0
author: UX Themes
author_website: (undefined)
parent_theme: Flatsome (flatsome)
theme_features: core-block-patterns, post-thumbnails, woocommerce, title-tag, automatic-feed-links, customize-selective-refresh-widgets, sensei, html5, menus, post-formats, widgets

### wp-parent-theme ###

name: Flatsome (flatsome)
version: 3.13.3
author: UX-Themes

### wp-themes-inactive (1) ###

Flatsome: version: 3.10.4, author: UX-Themes

### wp-mu-plugins (1) ###

Plugin Organizer MU: version: 10.1.5, author: Jeff Sterup

### wp-plugins-active (39) ###

ActiveCampaign for WooCommerce: version: 1.3.6, author: ActiveCampaign
Advanced Custom Fields PRO: version: 5.9.2, author: Elliot Condon (latest version: 5.9.6)
Advanced Order Export For WooCommerce (Pro): version: 3.1.6, author: AlgolPlus (latest version: 3.1.8)
AutomateWoo: version: 5.2.1, author: WooCommerce
Custom Post Type UI: version: 1.9.1, author: WebDevStudios
Disable WooCommerce Bloat: version: 2.4.4, author: ospiotr
Dokan: version: 3.0.11, author: weDevs (latest version: 3.2.6)
Dokan Pro: version: 3.1, author: weDevs (latest version: 3.1.1)
Front End PM PRO: version: 11.3.1, author: Shamim Hasan
Invoice Gateway For WooCommerce: version: 1.1, author: Rymera Web Co
Nav Menu Roles: version: 2.0.1, author: Kathy Darling
Newsletter: version: 6.9.4, author: Stefano Lissa & The Newsletter Team (latest version: 7.1.8)
PB SEO Friendly Images Pro: version: 4.0.4, author: Pascal Bajorat
Perfmatters: version: 1.7.1, author: forgemedia
Redirection: version: 5.1.1, author: John Godley
Relevanssi Premium: version: 2.10.3, author: Mikko Saari
User Switching: version: 1.5.7, author: John Blackbourn & contributors
WooCommerce: version: 4.6.1, author: Automattic (latest version: 5.3.0)
WooCommerce Advanced Bulk Edit: version: 4.4.4, author: George Iron
WooCommerce Google Analytics Pro: version: 1.10.0, author: SkyVerge
WooCommerce Order Status Manager: version: 1.11.3, author: SkyVerge
WooCommerce PDF Invoices & Packing Slips: version: 2.7.0, author: Ewout Fernhout (latest version: 2.8.3)
WooCommerce PDF Invoices & Packing Slips Professional: version: 2.3.0, author: Ewout Fernhout
WooCommerce Product CSV Import Suite: version: 1.10.41, author: WooCommerce
WOOCS – WooCommerce Currency Switcher: version: 2.3.4.1, author: realmag777
WP All Export – User Export Add-On Pro: version: 1.0.4-beta-1.2, author: Soflyy (latest version: 1.0.4)
WP All Export Pro: version: 1.6.2, author: Soflyy (latest version: 1.6.5)
WP Fastest Cache: version: 0.9.1.8, author: Emre Vona
WP Offload Media Lite: version: 2.5.3, author: Delicious Brains
WP Offload SES: version: 1.5.3, author: Delicious Brains
YITH WooCommerce Wishlist Premium: version: 3.0.9, author: YITH
Yoast SEO: version: 15.9.1, author: Team Yoast
Yoast SEO: WooCommerce: version: 13.9, author: Team Yoast

### wp-plugins-inactive (8) ###

Disable Emails: version: 1.7.0, author: WebAware
Flying Scripts by WP Speed Matters: version: 1.2.2, author: Gijo Varghese
GTranslate: version: 2.8.61, author: Translate AI Multilingual Solutions (latest version: 2.8.63)
Plugin Organizer: version: 10.1.5, author: Jeff Sterup
Query Monitor: version: 3.7.1, author: John Blackbourn
WooCommerce Stripe Gateway: version: 4.6.0, author: WooCommerce (latest version: 5.2.0)
Wordfence Security: version: 7.4.14, author: Wordfence (latest version: 7.5.3)

### wp-media ###

image_editor: WP_Image_Editor_GD
imagick_module_version: Not available
imagemagick_version: Not available
file_uploads: File uploads is turned off
post_max_size: 512M
upload_max_filesize: 512M
max_effective_size: 512 MB
max_file_uploads: 20
gd_version: bundled (2.1.0 compatible)
ghostscript_version: 8.70

### wp-server ###

server_architecture: Linux 5.10.2-x86_64-linode140 x86_64
httpd_software: Apache
php_version: 7.4.19 64bit
php_sapi: litespeed
max_input_variables: 10000
time_limit: 600
memory_limit: 6000M
max_input_time: 600
upload_max_filesize: 512M
php_post_max_size: 512M
curl_version: 7.76.1 OpenSSL/1.1.1k
suhosin: false
imagick_availability: false
pretty_permalinks: true
htaccess_extra_rules: true

### wp-database ###

extension: mysqli
server_version: 10.3.27-MariaDB
client_version: mysqlnd 7.4.19
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