Getting 403 error during installation

I am moving my clients site to a new Unix host server. Using V1.3.0 have installed SSL cert., setup SQL database, copied all files of the zencart installation, changed permissions as noted in the installation article. When I go to save system settings, I get a '403 Forbidden - Access is forbidden to the requested page:'
I've checked to insure the domain name was typed correctly. I have changed the server info on domain name definition but it has not resolved yet. Would this cause this error? I had to access the install program using the IP address but when defining the site in system settings, I used the real domain name. Can someone please help. I will include the entire error message below.
Thanks for anticipated help.

403 Forbidden
Access is forbidden to the requested page:

74.53.247.26/~ruthsdes/store/zc_install/index.php?main_page=phpbb_setup&language=english&physical_path=/home/ruthsdes/public_html/store&virtual_http_path=http://www. ruthsdesigns. com/store&virtual_https_path=https://www. ruthsdesigns. com/store&virtual_https_server=https://www. ruthsdesigns. com&enable_ssl=true&enable_ssl_admin=true&sql_cache=/home/ruthsdes/public_html/store/cache&is_upgrade= (port 80)
Please forward this error screen to 74.53.247.26's WebMaster.

That's your server's security systems trapping the very long URL parameters which contain multiple references to "http://", which is a common exploit method used by hackers.
Newer versions of Zen Cart use a better approach to passing information between pages. But to benefit from that you'll need to use a newer version of Zen Cart, which means upgrading.
You REALLY ought to be upgrading ASAP anyway, since your old version has known security vulnerabilities.

Your host probably won't be willing to disable mod_security and other security protections they have in place. So you might need to do your upgrade on the old host or on your own PC, and then move the upgraded version to the new server.

EVery article I've read says to NOT upgrade and move a site at the same time. I had planned to upgrade after I moved it and got it working properly. According to how much time I've had to keep this site down just doing this part, I now don't know when I could upgrade. It has been one problem after another, not just zencart but everything I touch. I inherited this site and the old webmaster would not give me all the info I needed... oh, don't go there.
Anyway, so you're saying because of the version I have and the error I'm getting, the only solution would be to upgrade now?
Thanks

Yes, unfortunately, for the reasons I mentioned earlier, upgrading before you move servers looks like your best option.

And you're right: you should upgrade BEFORE or AFTER a move, but not "during" a move. Else you'll never know whether something that's "not working" is a result of a server problem on the new server or something in your upgrade or something that just wasn't copied properly. It makes troubleshooting any move-related issues very very complicated if you do an upgrade during the move. And, since troubleshooting such problems involves the majority of steps involved in an upgrade, it makes sense to spend the time intentionally upgrading instead of troubleshooting without knowing what the real issues are.

One more question. I've already changed the server names to point to the new servers. When installing zencart, will it let me use the IP address instead of domain name? If not, I will have to change it back to the old servers then when I get the upgrade done, I will have to change it again to point to the new servers.
Whew! This is going to be ugly anyway I look at it. I've already had this site down for 3 days because I needed some information and I had to deal with finger pointing trying to get answers. Got that resolved, ran into another problem, got that resolved and now this! My client gonna be unhappy and I can't blame her. Because I'm new to zencart and I'm afraid of how long this process is going to take, according to some of the threads I've read.

Oh, can I upgrade to the newest version or do I have to go in sequence??

TzuLady:

Oh, can I upgrade to the newest version or do I have to go in sequence??
Answered here, in the questions section:
https://www.zen-cart.com/tutorials/index.php?article=98