Thanks for the suggestion LeonidS

Yes, I saw that solution already when I did a search Unfortunately, that solution didn't work on my server.

I'm running DirectAdmin control panel on the server, and I found out that there is a way to turn ModSecurity off for the one account from within DirectAdmin control panel, or turn off specific ModSecurity rules for the account. I prefer the latter to turn of specific rules. it will mean inspecting the Apache error logs to determine which rules are blocking the Submit and Save buttons on the UNA install. I'll be working on that again later this afternoon. I've just had other projects I am busy with too, this one is lower down the pecking order for my time.

Thanks.