My page is requiring login when it didn't previously

I created a site in CakePHP 5 a couple of years ago, and a couple of weeks ago my client reported that “one of the pages in the admin area isn’t working”. They last accessed it a year ago and it was ok then.

The admin area is behind a login, and allows the user to edit the pages on their website. Most of the “edit” screens just have a basic TinyMCE editor, but this one which has the issue is different as it’s a sort of photo gallery, so the edit screen allows the user to upload images, sort them in order, and add captions. When I try to view the edit screen it’s just showing me lots of mini login forms (I think it’s possibly that each image already on the page is showing a login form instead).

It’s been so long that I looked at the code that I can’t even remember where to start with this. Is there anything that could potentially cause individual images to require authentication, or anything along those lines? Any ideas would be much appreciated!

You start each debugging by viewing the logs and deleting the cache. Also, if the admin is logged in for that view / method, you can temporarily turn on debug mode. to see what the errors are.