Exception: Invalid id or tag 'page_ostowarzyszeniu_index.htm' : must use only [a-zA-Z0-9_]

#0 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Cache/Core.php(673): Zend_Cache::throwException('Invalid id or t...')
#1 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Cache/Core.php(302): Zend_Cache_Core::_validateIdOrTag('page_ostowarzys...')
#2 /virtual/pl/nwi/polski-zarzadca/pszn/application/public/controllers/IndexController.php(24): Zend_Cache_Core->load('page_ostowarzys...')
#3 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Controller/Action.php(133): IndexController->init()
#4 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Controller/Dispatcher/Standard.php(268): Zend_Controller_Action->__construct(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http), Array)
#5 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#6 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Application/Bootstrap/Bootstrap.php(97): Zend_Controller_Front->dispatch()
#7 /virtual/pl/nwi/polski-zarzadca/pszn/library/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run()
#8 /virtual/pl/nwi/polski-zarzadca/pszn/index.php(42): Zend_Application->run()
#9 {main}