PHP error log : is it due to a shut down ?? (1 reply)

Hi all,
I got this php error log on a wamp installed on a stand alone PC . My solution runs under WWW/ directory
What I need to understand is if the errors listed could be due to a brutal switch off of pc during the running of application. I'm not a tech guy so please use simple terms... ;-)

[08-Nov-2019 15:15:59 UTC] PHP Notice:  Undefined variable: _SERVER in C:\wamp64\www\Eos_Tat_Meter\_lib\lib\php\nm_ctrl_app_name.php on line 13

[08-Nov-2019 15:15:59 UTC] PHP Stack trace:

[08-Nov-2019 15:15:59 UTC] PHP   1. {main}() C:\wamp64\www\Eos_Tat_Meter\grid_tubes_labo_bin\grid_tubes_labo_bin.php:0

[08-Nov-2019 15:15:59 UTC] PHP   2. SC_dir_app_ini() C:\wamp64\www\Eos_Tat_Meter\grid_tubes_labo_bin\grid_tubes_labo_bin.php:4769