Sales.php not in install, however Developers Tool Kit is saying it is!

Okay, so I have started a sale which is showing up with this heading End of Financial Year Stock Clearance - 40% off! (whilst stocks last) on the home page and each categories page (like Featured Products does).

So I jumped into the Developers Tool Kit to edit the file to say 15%, and this is what it gave me:

**/home/amoraromatherapy/public_html/includes/languages/english/extra_definitions/sales.php

Line # 3 : define('TABLE_HEADING_CURRENT_SALES', 'End of Financial Year Stock Clearance - 40% off! (whilst stocks last)'); **

However, when I go to /includes/languages/english/extra_definitions/sales.php, the file doesn't exist! or in any of the subfolders in that folder.
In SaleMaker, my heading is "2026 End of Year Sale"

How is this even happening, and any suggestions on what I can do to override the message?
I have already tried to upload the Sales.php file from the install set, however it didn't make any difference, so I have removed it for now until we can fix this issue without it being there.

Thanking you in advance for your assistance

V1.5.7c, Database Patch Level: 1.5.7
v1.5.7 [2020-07-25 00:56:24] (New Installation-v157)
PHP Version 7.3.33
Plugin Manager page gives me a blank screen, here's a screenshot of all the mods.

You're seeing several indications of things going wrong.

The System inspection shows Display Logs not loaded, and you say Plugin Manager is a blank screen.

Start at https://docs.zen-cart.com/user/troubleshooting/blank_page/ to get the Plugin Manager going, then make sure Display Logs is loaded, as it will help you find errors.

Lastly, file editing should be done at your host's cPanel (or equivalent) file manager.