Just to add to this and to help the two guys above, on some of the sites I upgraded the “Upgrade Database” button didn’t show up at first, it only showed up when I clicked back into the Updates section.
Yes I upgraded the database.
I actually have ACF on about 9 websites and had already done all of those sites and upgraded the databases on those so was aware of the process, it was this final website that failed.
I will try doing it on a dev site next week and see what happens.
Thanks, we have rolled the website back to ACF 4.4.12 which is working fine now.
Strangely enough I can now also see updates for the add-ons in the updates section which weren’t there before.
I wonder if I update the add-ons first and then update ACF to 5 it would then work as planned?
I will setup a dev version of the site to try it out first I think.