I'm not testing locally as I want to make sure the emails trigger correctly. However, I have just done another test and the new server behaviour works perfectly but when accessing another page with the old code the page is blank.
I've just had a play around and commented out the old server behaviour code on the other page and it loads! There must be a conflict somewhere. I'd rather not keep this live as it's affecting visitors to my site where pages still have the old email server behaviour. Instead I have attached the two pages for you to see.
index.php (works perfectly with new server behaviour)
members.php (only loads if old server behaviour is commented out)
- Both files are running PHP v7.0 on the server.
To complete the migration, I am thinking that I may need to comment out all of the old email server behaviours and then work 1 by 1 to update each page in turn. This way it will cause as little disruption to visitors whilst I do this.