Error - cannot log in - backtrace

Hi,

I would be very happy if anyone could help me with this. I am using piwik 1.8.2 for weeks already and everything was fine, until today, when I tried to log in and the following error came up.

Now I cannot log in and view the reports. I am also not sure if the visits on the website are tracked.
I tried deleting all cookies but this didn’t help.

Error message 1 (just above the login field, in a pink box):
You must call Zend_Session::regenerateId() before any output has been sent to the browser; output started in /home/var/public_html/piwik/libs/Zend/Log/Writer/Stream.php/133

Error message 2 (at the top of the login site, in a yellow box):
There is an error. Please report the message (Piwik 1.8.2) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: base64_encode() has been disabled for security reasons in /home/var/public_html/piwik/core/Cookie.php on line 276

Backtrace -->
#0 Piwik_ErrorHandler(…) called at [:]
#1 base64_encode(…) called at [/home/var/public_html/piwik/core/Cookie.php:276]
#2 Piwik_Cookie->generateContentString(…) called at [/home/var/public_html/piwik/core/Cookie.php:189]
#3 Piwik_Cookie->save(…) called at [/home/var/public_html/piwik/plugins/Login/Login.php:138]
#4 Piwik_Login->initSession(…) called at [:]
#5 call_user_func_array(…) called at [/home/var/public_html/piwik/libs/Event/Dispatcher.php:284]
#6 Event_Dispatcher->postNotification(…) called at [/home/var/public_html/piwik/core/PluginsManager.php:633]
#7 Piwik_PostEvent(…) called at [/home/var/public_html/piwik/plugins/Login/Controller.php:157]
#8 Piwik_Login_Controller->authenticateAndRedirect(…) called at [/home/var/public_html/piwik/plugins/Login/Controller.php:71]
#9 Piwik_Login_Controller->login(…) called at [/home/var/public_html/piwik/plugins/Login/Controller.php:46]
#10 Piwik_Login_Controller->index(…) called at [:]
#11 call_user_func_array(…) called at [/home/var/public_html/piwik/core/FrontController.php:138]
#12 Piwik_FrontController->dispatch(…) called at [/home/var/public_html/piwik/core/Controller.php:659]
#13 Piwik_Controller->redirectToIndex(…) called at [/home/var/public_html/piwik/plugins/CoreHome/Controller.php:42]
#14 Piwik_CoreHome_Controller->redirectToCoreHomeIndex(…) called at [:]
#15 call_user_func_array(…) called at [/home/var/public_html/piwik/core/FrontController.php:138]
#16 Piwik_FrontController->dispatch(…) called at [/home/var/public_html/piwik/index.php:53]

Error message 3 (at the top of the login site, in a yellow box):
There is an error. Please report the message (Piwik 1.8.2) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: Cannot modify header information - headers already sent by (output started at /home/var/public_html/piwik/libs/Zend/Log/Writer/Stream.php:133) in /home/var/public_html/piwik/core/Cookie.php on line 170

Backtrace -->
#0 Piwik_ErrorHandler(…) called at [:]
#1 header(…) called at [/home/var/public_html/piwik/core/Cookie.php:170]
#2 Piwik_Cookie->setP3PHeader(…) called at [/home/var/public_html/piwik/core/Cookie.php:200]
#3 Piwik_Cookie->save(…) called at [/home/var/public_html/piwik/plugins/Login/Login.php:138]
#4 Piwik_Login->initSession(…) called at [:]
#5 call_user_func_array(…) called at [/home/var/public_html/piwik/libs/Event/Dispatcher.php:284]
#6 Event_Dispatcher->postNotification(…) called at [/home/var/public_html/piwik/core/PluginsManager.php:633]
#7 Piwik_PostEvent(…) called at [/home/var/public_html/piwik/plugins/Login/Controller.php:157]
#8 Piwik_Login_Controller->authenticateAndRedirect(…) called at [/home/var/public_html/piwik/plugins/Login/Controller.php:71]
#9 Piwik_Login_Controller->login(…) called at [/home/var/public_html/piwik/plugins/Login/Controller.php:46]
#10 Piwik_Login_Controller->index(…) called at [:]
#11 call_user_func_array(…) called at [/home/var/public_html/piwik/core/FrontController.php:138]
#12 Piwik_FrontController->dispatch(…) called at [/home/var/public_html/piwik/core/Controller.php:659]
#13 Piwik_Controller->redirectToIndex(…) called at [/home/var/public_html/piwik/plugins/CoreHome/Controller.php:42]
#14 Piwik_CoreHome_Controller->redirectToCoreHomeIndex(…) called at [:]
#15 call_user_func_array(…) called at [/home/var/public_html/piwik/core/FrontController.php:138]
#16 Piwik_FrontController->dispatch(…) called at [/home/var/public_html/piwik/index.php:53]

Thank you for help!

It looks like your admin made some changes in the PHP configuration, in particular:


Warning: base64_encode() has been disabled for security reasons in /home/var/public_html/piwik/core/Cookie.php on line 276

Ask your host to enable this function in your PHP.ini.

Thank you for the answer.
It must have been something with php configuration - the problem disappeared the next day.