Miltos-S

After cleaning up my functions.php the issue was solved for me.
To figure out if the problem was in my theme I did 2 things.
First I deactivated my theme and activated the twenty eleven theme. The problem was gone.
Second I reactivated my theme and temporarily emptied my functions file. The problem was gone again.
Some ideas that you may have already tried:
If you have multiple php tags in the functions try to eliminate them by having only one opening tag at the beginning and a closing at the end.
If you have other php files included in the functions check them too.

The only thing I wonder is why the previous version was working fine even without doing anything of the above…
Anyway maybe it was a chance to clean up my code a bit…!

Ok… problem solved!
This is not an ACF issue.
In my case it was the php tags in my functions.php
If you have space before or after the tags probably this causes the problem.

I just reverted back to 3.5.3 and the problem goes away here too.

Hi Elliot, thanks for the reply.
Yes exactly.
However in the previous page “Field Groups” the field number indicator for each group is correct IF the fields are 3 or less.
Same issue if you create a new group and then add a field.
When you click publish/update the field disappears from the “field order”.
(I am in localhost)

Exactly the same problem here when I updated to 3.5.4.1
Newly added fields are not displaying.
Same problem when I updated from another wordpress setup too.