where do I start? shop not working today

[Bryden McKinnie]

Customer notified me the shop is not working. I can log in to the back office. Tried a back up restore, no change.
https://chocolatefalls.co.uk
php7.1
using v1.5.5f
Where do I start to try and fix? No debug logs, last one was in March

[torvista]

Check the hosting is still 7.1 and ask them what they upgraded yesterday, whether they think it is related or not. Insist.

If there are no debugs, I think this means it is crashing before it has loaded the error reporting code...check server logs.

in application_top.php you can switch on the debug and see what is being loaded sequentially and probably where it stops loading.

[Bryden McKinnie]

Hi torvist,
PHP was only updated to 7.1 from 7.0 today. I've had no orders since Tuesday so could have been not working since then. No help when the website is up with no errors listed on the home page. Back office fine.
found the error logs ad looking back to Wednesday
[04-Jun-2019 23:04:10 UTC] PHP Fatal error: Uncaught Error: Call to undefined function ereg_replace() in /home/chocolat/public_html/includes/templates/##########_temp/common/tpl_header.php:98
Stack trace:
#0 /home/chocolat/public_html/includes/templates/##########_temp/common/tpl_main_page.php(129): require()
#1 /home/chocolat/public_html/index.php(97): require('/home/chocolat/...')
#2 {main}
thrown in /home/chocolat/public_html/includes/templates/##########_temp/common/tpl_header.php on line 98

[torvista]

change your hosting php back to 7.0 and start work on upgrading your development copy to 1.56b.

[mc12345678]

Not sure if you picked up on torvista's clues, but basically it appears that if you upgrade the core fileset and then your template (the template is what issued the fatal error in the message provided) and do this in a development environment where mistakes can be made without impact to the live site, then should be all clear when the necessary file changes are appropriately incorporated into the live site.