"Could not analyse class: maybe not loaded or no autoloader?" - typo3

Question

I created (my first) extension with one viewhelper.
Oops, an error occurred!
Could not analyse class:My\Mlv\ViewHelpers\Format\ReplacenewlinesViewHelper maybe not loaded or no autoloader?
In use (with news):
{namespace m=My\Mlv\ViewHelpers}
{newsItem.bodytext -> m:format.replacenewlines()}
Directory tree of extension:
typo3conf/ext/mlv
ext_emconf.php (copied from another ext)
/Classes
/ViewHelpers
/Format
ReplaceNewLinesViewHelper.php
ReplaceNewLinesViewHelper.php:
<?php
namespace My\Mlv\ViewHelpers\Format;
/**
* Replaces newlines in plain text with <br> tags.
*
* #author johndoe33
* #package Mlv
* #subpackage ViewHelpers\Format
*/
class ReplaceNewLinesViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper {
/**
* Replaces newlines in plain text with <br> tags.
*
* #param string $content
* #return string
*/
public function render($content = NULL) {
if (NULL === $content) {
$content = $this->renderChildren();
}
$content = str_replace( "\n", '<br>', $content );
return $content;
}
}

Answer 1

You need to use camel case in the view helper invocation:
{newsItem.bodytext -> m:format.replaceNewLines()}
Furthermore you may need to define an autoload definition in your ext_emconf.php if you're using TYPO3 >=7.6 (reinstall the extension after doing so):
'autoload' => array(
'psr-4' => array('My\\Mlv\\' => 'Classes')
)
For more information see: http://insight.helhum.io/post/130876393595/how-to-configure-class-loading-for-extensions-in