It sounds to me like you may have added the module attribute inside your system.xml:
<?xml version="1.0"?>
<config>
<sections>
<homebanner translate="label" module="homebanner">
...
</homebanner>
</sections>
</config>
In the above, module="homebanner" causes Magento to require a default helper class (Chris_Homebanner_Helper_Data) in your module when accessing admin, but you haven't defined helpers in your config.xml. You can either remove module="homebanner" from your system.xml, or add helpers to your config.xml and create a helper class. To create a helper, in config.xml:
<?xml version="1.0"?>
<config>
...
<global>
...
<helpers>
<homebanner>
<class>Chris_Homebanner_Helper</class>
</homebanner>
</helpers>
...
</global>
...
</config>
And then create the actual helper class, Chris/Homebanner/Helper/Data.php (it doesn't need any methods for this application):
<?php
class Chris_Homebanner_Helper_Data extends Mage_Core_Helper_Abstract
{
}
I find the whole XML thing difficult so I am sympathetic to your cause here.
It looks to me like there is a discrepancy with your class name and your block XML
ie
class Crusader_CLHomePage_Block_Qwerty extends Mage_Core_Block_Template
and
<block type="core/template" name="homepage" template="crusader/home.phtml">
<block type="crusaderhome/qwerty" name="homeads" as="homeads" template="crusader/homeads.phtml" />
</block>
Let's start with the block type and work backward. I think here I would expect to see something like
<block type="crusader_home/qwerty" ...
and that type would refer Magento to the class
Crusader_Home_Block_Qwerty extends Mage_Core_Block_Template
Continuing to work backward on this tack, the file app\code\local\Crusader\CLHomePage\etc\config.xml would need to be modified to something like
<global>
<blocks>
<crusader_home>
<class>Crusader_Home_Block</class>
</crusader_home>
</blocks>
</global>
It points Magento to all classes starting 'Crusader_Home_Block_*'. And now I think you need to rename your module Crusader_Home instead of Crusader_CLHomePage and change the folder names accordingly...
AND / BUT I strongly recommend you change your module name. Only ever use one capital letter at the start of the module name not three and don't put capital letters in the middle of the name either.
You may want to look into some of the tools available for generating modules. I find them very useful for avoiding typing errors. I use this one by the very clever people at MGT Commerce (it has simplicity on its side) and this one is all-encompassing and an astonishing piece of coding by Silk Software.
***EDIT following comments below
Additionally based on the error log I think the problem is that Magento can't find your class file. So double-check the caches are refreshed or off, particularly XML cache, and that the compiler is off or re-enabled.
Best Answer
As already explained in your other question and as @Fabian Blechschmidt states, you simply just disable module (admin > config > system > advanced) and then remove the entry from the database table
core_resourceand clear cache/sessions as necessary. This removes the install information for that extension from Magento. Then you would delete the necessary files and folders relating to that extension.If this isn't working for you, then you've either done something wrong, your Magento install has more serious issues or your extension is inserting multiple traces and references to it in other places in the structure/database.