In case this has happened to other users I though I would let you know how I fixed the issue.
Thank you - this will help others when searching forums.
First issue was that the data for a new users "Business Name" and "Phone Number" would not save in the backend i.e. they (new user) would fill in all the required details at registration which included their Business Name and Phone Number but when I opened their details in the "User Management" section those details were missing. Even if i put the details in myself from the backend and saved it the details would not remain.V
Wondering if CB Tools run here would show this and fix the fields.
This started to happen after I upgraded from CB 1.2 to CB 1.3.1.
This information is missing from your initial post (it stated that issue started when you upgraded from CB 1.4 to CB 1.7).
Then after I upgraded from CB 1.3.1 to CB 1.4 the save button would not work, I also tried an upgraded to CB 1.7 to see if that would fix it but no luck.
The fix turned out to be simple, the two fields "Business Name" and "Phone Number" must have corrupted during the upgrade from CB 1.2 to CB 1.3.1. which I was not aware of. All I did was to delete those fields and re-create them and now everything works perfectly. (I wish I had thought of that sooner). I upgraded to CB 1.7 before I did this but I don't think it matters what version is running when it is done.
Maybe CB Tools run here would have helped also.
I hope this fix helps someone out as I have spent 3 days going through a lot of trial and error but all I needed to do was delete a couple of corrupted fields and re-create them.
I ran CB tools (all of them) every time I upgraded and I got green every time. for three days I tried everything, as i said I wish I had thought about the simple things first.
Yes I made an error in my first post about when the problem started but I don't think that would have made a difference to any help. Next time I will be careful and make sure the version info is correct. The issue that I said started when I upgraded from 1.4 to 1.7 was the save button didn't work. I was wrong, the save button didn't work after upgrading from 1.3.1 to 1.4, again I don't think this would have changed any help I got.
At the end of the day I just hope that this will help others in the future.