Error when I try to notify customer that item was shipped

-- HikaShop version -- : 5.0.0
-- Joomla version -- : 4.4.0
-- PHP version -- : 8.1
-- Browser(s) name and version -- : Firefox 119.0

Hi,

I'm trying to notify the customer that the item has shipped, but I get this error when the program evidently tries to access a mailing routine or something.

Hi,

This error message indicates that something somewhere uses code which isn't compatible with Joomla 4.
Turn on the "debug" setting of the Joomla configuration and reproduce the error. You should then get more information on the error page which will allow us to tell you what to do.

Hi,

Actually after I turn on debug, the message said it was from a Hikashop file from 2017 that was located in the media/com_hikashop/mail directory. There are a number of files there with an added ".modified" to it. I don't remember doing any modifications, but I've changed all those file extensions from .php to .old to prevent any future issues.

I'm assuming that these files from 2017 have all been superceded, as there are exact filenames (without the .modified) in that directory.

Hello,

This file modified is created when a custom is created in order to modify your emails, the goal is to avoid overwriting your changes with a new update.
But this also means that these files are not updated with the new Jommla, HikaShop or Php standards, explaining this type of problem.
Happy to read that you have solve your issue.

Regards