Upgrading Drupal

I am in the midst of upgrading 5.9 to 6.3, following upgrade.txt. Everything backed-up and transferred, all modules turned-off, default theme and user. Will not process update.php. Basically freezes to a blank screen and when I try to get to any page..a flood of db errors. I have tried most of everything I have found here re this...help please!

sjmo2

I am currently using Drupal 5.x and I have established a development site for Drupal 6.3. On my Drupal 5.x site, one of my pages uses Javascript. It shows up perfectly in both Firefox 2.0 and Internet Explorer 7.0. The page can be viewed here: http://www.sikhism.com/makehomepage

I upgraded from 5 to 6, installed the contributed modules (views, CCK, Content Taxonomy), installed my custom theme (modified Deco), and activated the Update Status Module.
Now I cannot load any admin pages and all. The site still loads, but nothing admin.

Any help would be appreciated.

MB.

Dear all

I have no idea what to do: I just upgraded the following modules
BUEditor
globaldirect
imce
token

and I also installed
piwik
poormanscron

everything went fine - no errors etc.
But when I took my site on-line (that is out of maintance mode) I got this in

Redirect Loop
Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

PLS helo: whats gone wrong? how to fix it?

What does it mean if my drupal works after I have run update.php, but then starts showing 'Internet Explorer cannot connect' after about an hour or so, with the following error message:

PHP Fatal error: Call to undefined function filter_xss_bad_protocol() in /user/htdocs/includes/common.inc on line 850

Please help!

I became admin of a drupal site which and as been dormant for a while, its 4.7, so before doing anything, i decided to upgrade it to 5.9.

i copied the whole site to a test server, including the db, and committed the procedure to upgrade. The site uses the Fern theme, which only is supposed to work in 4.7.

I ignored this and went ahead with upgrading anyhow.