Fatal error: Uncaught Error: Class 'Sns_Simen_Block_Mainmenu' not found in /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php:491 Stack trace: #0 /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('Sns_Simen_Block...', Array) #1 /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('simen/mainmenu', 'mainmenu.top') #2 /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('simen/mainmenu', 'mainmenu.top') #3 /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element)) #4 /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php(206): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element)) #5 /var/ in /var/www/vhosts/simple-city.gr/httpdocs/app/code/core/Mage/Core/Model/Layout.php on line 491