J-BusinessDirectory - JB 5.02 - Language file for front-end templates not loading

Hi,

The issue is usually generated by an error on language file.
The first line of the custom text area is appended in the last line of the main language file.
Please edit the language in the general settings -> language tab and check where the custom text is starting on the main language file (the last lines of the file)

I check the language files and they work in production (which I haven't upgraded). I also tried the language file without the custom add-on file, but no luck.

I believe the issue is with the file not being found when JBD is trying to load it. As I had moved the installation from a subdomain to a folder, it could be related to the file-path not being set correctly somwhere.

I was hoping someone could provide a hint where I can check for that. Which php-file is loading the language file (.ini file) for the front-end template (e.g. that is rendering the listing details).