In Default, Magento provide global messages(flash messages) to display success,Error and Notice after page loading.For us, global messages is not working anywhere ( front-end and admin-side ) . If anyone faced this issue, please provide your suggestion to resolve this issue .Thanks!
Could you add a code on how you display an error message?
This is the way you could add a Magento notification in admin panel
Mage::getSingleton('adminhtml/session')->addSuccess("Message"); //or addError();
If you are using Nexcessnet_Turpentine, check if the extension is enabled at
Admin -> System -> Configuration -> Advanced -> Developer -> Disable Modules Output
because Nexcessnet_Turpentine_Block_Core_Messages rewrites Mage_Core_Block_Messages