Hi,
Is the error "Undefined variable: _SERVER" due to an untimely shutdown of the PC, I don't know, but I would say that I would be surprised.
The array $_SERVER['key'] is a predefined variable that is relevant to the server and the system environment, the entries being created by the server itself at each server startup. See : [
www.php.net]
The only Apache stop not done correctly is this one:
[Wed Jan 01 13:29:38.022070 2020] [mpm_winnt:notice] [pid 3800:tid 396] AH00428: Parent: child process 6040 exited with status 255 -- Restarting.
What can possibly happen during a power outage is that files in caches and pending SQL writes are not written when they are written during a "normal" shutdown. Therefore, it is possible that a php file may be "spoiled".
---------------------------------------------------------------
Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons