@alwaysblank, thank you for the reply! I do appreciate your help as ever. Sorry if I was a little unclear. To add a little context then, I’ve been developing my site locally for a few days on my Mac - standard config, Apache, PHP 7, OS 10.13.2. You may remember that a few days ago in order to access some ACF fields I updated to version 2 of the controller on my dev site and you helped me with changing a couple of namespaces and filenames at that time. I’d already set up a staging site for this project and it was working fine but I hadn’t deployed anything since running composer update on the local dev. My usual deployment process is simply to push my theme files to Bitbucket, then on the staging server pull the changes. I then upload the dist file via FTP and finally I have a plugin which automatically uploads the database and the media library files - I’ve done this numerous times already and am very happy with it as a general rule. I did all that and realised when I viewed the staging site that none of the ACF stuff was displaying, the front page was displaying but I just had holes where my ACF field data should have been. Thats when I remembered that I’m an idiot and hadn’t run composer update on the staging site, therefore my front page would not have access to the ACF data. So that’s what I did, ssh’d in to the staging server and ran composer update in the theme folder. It updated fine, no errors. But now when I view the staging site I’m getting the above error.