Hi Jerome,
Thanks for reaching out, and I’m sorry for the trouble here! If you’re making changes to template files for our plugins, please make sure that you are correctly duplicating them and placing the files in the proper folder as outlined in our Themer’s Guide. Template files that are stored in the correct location as detailed in our guide won’t be overwritten by plugin updates.
For your 503 errors, we’d be glad to do a bit more troubleshooting to see what might be happening there. To get things started here, would you be willing to take a moment to share your system information with us? This Knowledgebase article provides instructions on how to obtain this info and share it securely with us–let us know if you should have any issues as you’re working through the steps!
Thank you!