I put my 1.5.7 -> 1.5.8a upgrade live last night and generally its working fine, except I'm getting a lot of warnings thus -

[01-Mar-2024 11:15:04 xxx] PHP Warning: Undefined array key "languages_id" in /home/xxx/zencart/includes/extra_configures/enable_error_logging.php on line 84
[01-Mar-2024 11:15:04 Australia/Sydney] Request URI: /zencart/index.php?main_page=page_not_found, IP address: xxx, Language id
#0 /home/xxx/zencart/includes/init_includes/init_sessions.php(144): zen_debug_error_handler()
#1 /home/xxx/zencart/includes/autoload_func.php(40): require_once('/home/xxx/...')
#2 /home/xxx/zencart/includes/application_top.php(237): require('/home/xxx/...')
#3 /home/xxx/zencart/index.php(25): require('/home/xxx/...')
--> PHP Warning: Undefined array key "HTTP_USER_AGENT" in /home/xxx/zencart/includes/init_includes/init_sessions.php on line 144.

never saw anything like this on my test server so a bit perplexed?