Website totally blank after uploading new files under public_html

Hello!

I had to create a simple website on WordPress for school and now that it was ready, I transferred all the dev files (public_html) onto the prod, because we can’t just change the URLs, and we want to keep the prod URL. So, I copied all files on my computer (in case I made mistakes, which it seems I did), deleted the prod files and added the dev files (all only under public_html). Also, I made sure to change the DB_Name/user/password of the wp-config file for the prod ones (because it would only redirect to the dev website if I had not changed them). However, now, the prod website is completely blank, as if there was nothing. When I try to right click, see source code, there is literally nothing, no lines. I can access the WordPress ‘backend’, but it’s as if nothing changed : all the ‘old’ pages and articles are there, and I can edit them, but I can’t ‘View’ them, it’s all blank. No other sign of the transfer or any of the dev content.

prod : lippa.recherche.usherbrooke.ca
dev : lippadev.recherche.usherbrooke.ca

I tried to follow “Moving WordPress” guidelines but I ended up changing the dev url the the prod url IN wordpress, and so now I can’t even access the wordpress back end of the dev one. (wp-admin page of the dev just redirects me to the wp-admin page of the prod). If anybody can help me with that as well, I would be forever grateful!

I am a simple communication student and I tried getting help from my tech university center (as the hosting is from our university), but they told me this is not part of what they help for. I tried getting help from the database software, but it’s Ajaxplorer and I learnt it hasn’t been supported since at least 5 years. Any help or information will be very much appreciated – even if it’s telling me who I should be asking for help! I’m completely lost and don’t know where to go from here, I am trying very hard to not panic.

Thank you very much!

The page I need help with: [log in to see the link]