Will form and print format customisation stop an update?

Thank you @rmeyer for taking the time !

Yes, it was my understanding as well and that is why I limit my customisation work to
that only.

Since i made this post, I did some more digging and realised that, during the installation,
I had to make a fix …

My manual install was done according to this link .

But it breaks at some point, for which I found a fix … according to this link …

So I actually edited the init.py file.

I thought that this could cause it but checked this on another 13 server by first using your
suggested command…

git status
and I got a response : nothing to commit, working tree clean

and on that server ( multinenant ) the update went through with no problem on all sites.
So it cannot be the init.py file that I changed.

Let me return to my first server, I have something to work with , from your suggestion.

Thank you again. Appreciate you taking the time.