I've just downloaded and installed the latest pre-test of emacs
(26.0.91) and run it. After sorting out several config quirks I was able
to load it and use it - except, in org-mode it had lost the ability to
line-wrap at 100 characters, as I usually have it! But with the exact
same config using emacs-25.3.3 line-wrap returned!

So how can I use the emacs-26 version and also line-wrap please?

Thanks
Sharon.
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Debian 9.3, fluxbox 1.3.7, emacs 25.3.2, org-mode 9.1.6-10-g0c9329-elpaplus