Hi @darrenc4 ,
Thanks for reaching out!
This would indicate that some function named filter_upsells_order
was passed to call_user_func_array
, however that function was not found. You can read about the PHP call_user_func_array
function here:
https://www.php.net/manual/en/function.call-user-func-array.php
This could be coming from a plugin that you currently have active on your sites. As a first step, please could you disable all plugins except for WooCommerce and see if the problem persists?
If the problem is no longer present, to figure out which plugin is causing the problem, reactivate your other plugins one by one, testing after each until you find the one causing conflict.
Additionally, if you have any custom code added to your sites, please also temporarily disable this to see if this makes any difference?
If the issue is still not resolved after this, please could you share a copy of the following:
– System status report: WooCommerce > Status. Select ‘Get system report’ and then ‘Copy for support’.
– Fatal errors: a copy of any fatal error log found under WooCommerce > Status > Logs
Once you do this, you can paste your response here.
Thanks!