CMS Made Simple Forums

I tried to upgrade a site that's currently running 1.3.1.  I went directly to 1.6.6 and was met with a blank screen.  It never bothered to enter the upgrade process at all.  This seemed like a server burp to me so I deleted the CMSMS folders and *.php files (except config.php) in the root so that there would be no overwriting, just uploading fresh files. Then I got 500 Internal Server errors. 

Fortunately, I was able to revert back to the original CMSMS files since I'd done a complete site back up prior to this.

Do you think the problem is that I need to incrementally upgrade, 1.4.x, 1.5.x, 1.6.x, in order to preserve the database structure?  Can you think of any other reasons why CMSMS would throw out blank pages like that?

Thanks for any assistance. 

P.S. I upgraded several other CMSMS sites this past weekend, but the oldest was 1.4.x and it went straight to 1.6.6 without a hitch.

I upgraded from 1.2.4 with no problems (took maybe 30min).

I do not trust overwriting. Either upgrade incrementally, or do a full backup per my instructions, and reinstall newest version (for very old versions of cmsms)

I agree and I think that's what I'm going to do from now on, delete the folders (other than /uploads and /images) before upgrading, so that I am assured of having the latest files on the server.  I used to always backup my modules folder but now that it's become so easy to install and upgrade modules from with the administration panel, there's no need for that any more. (Thanks, Devs!!!!)

per my instructions = http://mkrd.info/software-discussions/cms-made-simple/backin-up-and-restoring-cmsms.html