BuddyPress.org

I’m running WordPress 4.7.5 on XAMPP v3.2.2. Directory C:\xampp\htdocs\WP. I think my installation is in a sub directory as I haven’t delete the localhost “dashboard” yet. Or, inside xampp’s htdocs folder there are folders named ‘dashboard’, ‘xampp’ and ‘wp'(Which i’ve install my wordpress).
I did not upgrade from previous version of WordPress.
Yes, wordpress was functioning perfectly before I’ve decided to install BuddyPress.
I have tried to install buddypress 2.4.5.

And an error appeared after activating the plugin:
Fatal error: Uncaught Error: [] operator not supported for strings in C:\xampp\htdocs\WP\wp-content\plugins\buddypress\bp-activity\bp-activity-loader.php:269 Stack trace: #0 C:\xampp\htdocs\WP\wp-includes\class-wp-hook.php(298): BP_Activity_Component->setup_admin_bar(”) #1 C:\xampp\htdocs\WP\wp-includes\class-wp-hook.php(323): WP_Hook->apply_filters(NULL, Array) #2 C:\xampp\htdocs\WP\wp-includes\plugin.php(453): WP_Hook->do_action(Array) #3 C:\xampp\htdocs\WP\wp-content\plugins\buddypress\bp-core\bp-core-dependency.php(115): do_action(‘bp_setup_admin_…’) #4 C:\xampp\htdocs\WP\wp-includes\class-wp-hook.php(298): bp_setup_admin_bar(Object(WP_Admin_Bar)) #5 C:\xampp\htdocs\WP\wp-includes\class-wp-hook.php(323): WP_Hook->apply_filters(NULL, Array) #6 C:\xampp\htdocs\WP\wp-includes\plugin.php(515): WP_Hook->do_action(Array) #7 C:\xampp\htdocs\WP\wp-includes\admin-bar.php(83): do_action_ref_array(‘admin_bar_menu’, Array) #8 C:\xampp\htdocs\WP\wp-includes\class-wp-hook.php(298): wp_admin_bar_render(”) #9 C:\xampp\htdocs\WP\w in C:\xampp\htdocs\WP\wp-content\plugins\buddypress\bp-activity\bp-activity-loader.php on line 269

I did not upgrade from previous version of BuddyPress.

Slider Revolution
Vibe Course Module
Vibe Custom Types
Vibe ShortCodes
WooCommerce
WooCommerce PayPal Express Checkout Gateway
WooCommerce Stripe Gateway
WPLMS Assignments
WPLMS Customizer Plugin
WPLMS Dashboard
WPLMS Front End

I am running WPLMS (https://themeforest.net/item/wplms-learning-management-system/6780226) V.3.0.1

I did not modify the core files of the theme and WP in any way.

I’m not sure if I have custom functions in bp-custom.php

I have used a newer version of WordPress (4.8.1) and BuddyPress (2.4.5) = failed (got similar error)
I’ve reinstalled and tried to install BuddyPress (2.5.5) = failed same error
Again, I tried to use BuddyPress (2.9.1) and again failed.