I need help removing PHP notice from a plugin

I would like to remove this notice message from the following plugin:
PHP Notice: Array to string conversion in /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php on line 269"
It is no longer maintained by the developer.

    kalico

    Thanks Ash,

    That got rid of the problem -- but now there's another one! Here it is, with the backtrace.

    `Array to string conversion
    Backtrace from notice
    In /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php [line 271]:

    [line ?] calling process_error()
    /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php [line 271] calling array_intersect_assoc()
    /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php [line 29] calling shortcode_settings()
    /var/www/html/wp-content/plugins/bowe-codes/bowe-codes.php [line 147] calling __construct()
    [line ?] calling register_shortcodes()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/bowe-codes/includes/actions.php [line 22] calling do_action()
    [line ?] calling bowe_codes_register_shortcodes()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/bowe-codes/includes/actions.php [line 18] calling do_action()
    [line ?] calling bowe_codes_register()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/bowe-codes/includes/actions.php [line 14] calling do_action()
    [line ?] calling bowe_codes_init()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/buddypress/bp-core/bp-core-dependency.php [line 235] calling do_action()
    [line ?] calling bp_init()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-settings.php [line 449] calling do_action()
    /var/www/wp-config.php [line 128] calling require_once()
    /var/www/html/wp-load.php [line 42] calling require_once()
    /var/www/html/wp-blog-header.php [line 13] calling require_once()
    /var/www/html/index.php [line 17] calling require()'

    If this is going to take more than a few fixes to keep it running, I may need to look for another solution. Here's the plugin in Github in case it helps.

    Thanks!

    kalico

    Here's another twist: this plugin is deactivated, but it's still throwing errors in debug -- only when I network activate a plugin from the "all" (unfiltered) view (Network >> Plugins). Then, if I reload the admin page after activating, the error goes away.

    If I click on "recently active" plugins to filter my plugin list, and then network-activate a plugin from the filtered list, the errors do not show up.

    If I activate a non-network plugin (i.e., activate a plugin on a sub-site) it doesn't happen.

    Weirdly, the error in this situation is referencing line 269 -- which is blank.

    Here is the error message, with backtrace (note this is ONE error, with backtrace; not multiple errors. But there are multiple instances of this same error showing up under the conditions described above.):

    Array to string conversion
    Backtrace from notice
    In /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php [line 269]:
    
    [line ?] calling process_error()
    /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php [line 269] calling array_intersect_assoc()
    /var/www/html/wp-content/plugins/bowe-codes/includes/shortcodes.php [line 29] calling shortcode_settings()
    /var/www/html/wp-content/plugins/bowe-codes/bowe-codes.php [line 147] calling __construct()
    [line ?] calling register_shortcodes()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/bowe-codes/includes/actions.php [line 22] calling do_action()
    [line ?] calling bowe_codes_register_shortcodes()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/bowe-codes/includes/actions.php [line 18] calling do_action()
    [line ?] calling bowe_codes_register()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/bowe-codes/includes/actions.php [line 14] calling do_action()
    [line ?] calling bowe_codes_init()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-content/plugins/buddypress/bp-core/bp-core-dependency.php [line 235] calling do_action()
    [line ?] calling bp_init()
    /var/www/html/wp-includes/class-wp-hook.php [line 298] calling call_user_func_array()
    /var/www/html/wp-includes/class-wp-hook.php [line 323] calling apply_filters()
    /var/www/html/wp-includes/plugin.php [line 453] calling do_action()
    /var/www/html/wp-settings.php [line 449] calling do_action()
    /var/www/wp-config.php [line 128] calling require_once()
    /var/www/html/wp-load.php [line 42] calling require_once()
    /var/www/html/wp-admin/admin.php [line 31] calling require_once()
    /var/www/html/wp-admin/network/admin.php [line 13] calling require_once()
    /var/www/html/wp-admin/network/plugins.php [line 11] calling require_once()