Upgrading Drupal

After upgrading to 6.14 I had problems every time I did something with a module. A message about a fatal error would come up but if I went back a page it disappeared. Denial was working for me until two weeks ago. I changed a module (can't remember which one) and got a fatal error message. I did what it suggested and another came back, ad nauseam.

Hi all,

I'm taking over a couple of Drupal sites and my technical skill and knowledge of Drupal is still limited. Therefore, any advice is appreciated.

I had one 4.7 Drupal site, one 5.1 Drupal site and one 6.14. Recently, I've upgraded the 5.1 to 5.21 and 6.14 to 6.15 without any problem. The sites are running as expected.

I upgraded to 6.15 and theme Fervens 6.2.3.

All seems OK except the sidebars won't display and I had a error that suggested there was a problem with line 1771 in my theme inc file. This is the section of that file;

Here's the complete error:

Fatal error: Call to undefined function: filter_xss_bad_protocol() in /home/twelvizm/public_html/includes/common.inc on line 1039

Should I just completely re-install from my backup?

Hi Folks

In settings.php: $base_url = 'http://www.4net.cc/drupal';

But all internal links are shown as "http://www.4net.cc/xxx"

Any ideas ???

I tried to update Views, Imagefield and Quick Tabs modules but I can't run update.php

I get the following error: