Keep in mind that the Tutsplus Magento Fundementals course is old and needs a few changes to get things to work
I think the course has been updated subsequently please check it on the following link to Tutsplus
Episode 10: Creating our First Controller
Remember to type it word for word, I used <uses> instead of <use> in the following code:
<frontend>
<routers>
<demo>
<use>standard</use>
<args>
<module>Tutsplus_Demo</module>
<frontName>demo</frontName>
</args>
</demo>
</routers>
<frontend/>
Episode 15: Putting it all Together
Remember to ensure that your etc/config.xml,has the <block> section so Magento knows where to look, under <globals>.
<blocks>
<demo>
<class>Stephen_Demo_Block</class>
</demo>
</blocks>
Also make sure that the handle for the sayHello Action of the Index controller is of the format:
Module_Controller_Action and not Namespace_Module_Controller_Action
Should be:
<demo_index_sayhello> NOT <tusplus_demo_index_sayhello>
