Possible Duplicate:
Headers already sent by PHP
I've a backend and fronted error in Magento, other posts on Stackoverflow and Google didn't lead to a solution.
The error Magento is giving:
Cannot send headers; headers already sent in /home/blackber/public_html/lib/aitpagecache/config.php, line 110
Trace:
#0 /home/blackber/public_html/lib/Zend/Controller/Response/Abstract.php(114): Zend_Controller_Response_Abstract->canSendHeaders(true)
#1 /home/blackber/public_html/app/code/core/Mage/Core/Model/App.php(1181): Zend_Controller_Response_Abstract->setHeader('Content-Type', 'text/html; char...')
#2 /home/blackber/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(80): Mage_Core_Model_App->getResponse()
#3 /home/blackber/public_html/app/code/core/Mage/Core/Model/Url/Rewrite.php(171): Mage_Core_Controller_Varien_Front->getResponse()
#4 /home/blackber/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(147): Mage_Core_Model_Url_Rewrite->rewrite()
#5 /home/blackber/public_html/app/Mage.php(459): Mage_Core_Controller_Varien_Front->dispatch()
#6 /home/blackber/public_html/index.php(114): Mage::run('bbunlock', 'website')
#7 {main}
Didn't change anything the last days and 2 shops are currently offline (same Magento installation).