'An unknown error occurred.' when trying to add new custom widget I am hoping that somebody can help with this issue.

I followed this excellent tutorial on creating a custom widget in Craft. On completion, I uploaded the plugin to the /craft/plugins/ directory, visited the page at /admin/settings/plugins and installed the plugin. All fine so far. Then, on returning to the dashboard, I clicked on New Widget, and selected the name of the widget. Following this, a message flashed up saying 'An unknown error occurred.' and little else happened.

It's probably user error, but if you could point out what I might have done incorrectly, that'd be useful.

My Plugin Structure

The plugin's called Adlister and the widget's called Alu, so in /craft/plugins/adlister/ I have two folders ( templates/ and widgets/ ), and a file: AdListerPlugin.php. Within templates/ is a file: AluWidget.html and within widgets/ is AdLister_AluWidget.php.

File Contents

AdListerPlugin.php

&lt;?php
namespace Craft;

class AdListerPlugin extends BasePlugin
{
    function getName()
    {
         return Craft::t('AdLister');
    }

    function getVersion()
    {
        return '1.0';
    }

    function getDeveloper()
    {
        return 'Mark Syred';
    }

    function getDeveloperUrl()
    {
        return 'http://www.sypo.uk';
    }
}


AluWidget.html

&lt;p&gt;Click to perform &lt;a href="http://example.co.uk/adlister-update.php?numDays=1"&gt;a daily update&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;Click to perform &lt;a href="http://example.co.uk/adlister-update.php?numDays=3"&gt;an update on a Monday&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;Click to perform &lt;a href="http://example.co.uk/adlister-update.php?numDays=7"&gt;a weekly update&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;Click to perform &lt;a href="http://example.co.uk/adlister-update.php?numDays=30"&gt;a monthly update&lt;/a&gt;.&lt;/p&gt;


AdLister_AluWidget.php

&lt;?php
namespace Craft;

class Adlister_AluWidget extends BaseWidget
{
    public function getName()
    {
        return Craft::t('Adlister Update');
    }

    public function getBodyHtml()
    {
        return craft()-&gt;templates-&gt;render('adlister/AluWidget');
    }
}


Any help that anyone could provide would be much appreciated.

With kind regards,

Mark

UPDATE

I don't know if this has any bearing, but the version of Craft I'm running is 2.6.2911.
I feel quite embarrassed, but I have finally got this thing working. The error that I had made was within AdLister_AluWidget.php. I had written at line 4: class Adlister_AluWidget extends BaseWidget instead of what it should have been: class AdLister_AluWidget extends BaseWidget. So, AdLister should have been written with an UPPER-CASE 'L' and not lower-case. If anyone else is struggling, hopefully my error will help them.

The correct code in full:

&lt;?php
namespace Craft;

class AdLister_AluWidget extends BaseWidget
{
    public function getName()
    {
        return Craft::t('Adlister Update');
    }

    public function getBodyHtml()
    {
        return craft()-&gt;templates-&gt;render('adlister/AluWidget');
    }
}