Hello, it’s my first problem with Piwik ;o
After using auto-update in web gui and DB upgrade from CLI (as I always do), one of the widget is saying "Zend_Session is currently marked as read-only."
I tried to restart webserver (nginx) and php (php5-fpm), relogging piwik account, using private session in browser but widget just doesn’t work 
Hi! I have exactly the same problem after the update of piwik. Another user in the german forum tested this issue too and it is reproducable.
Kind regards
Jan
Thx for info, I’m not alone then 
I hope that my stats after fix will be consistent.
Hi Piwik Comm!
Im having the same issues after update 2.11.1 :
1. GOALS not working.
“Zend_Session is currently marked as read-only.”
2. Visits Overview (with graph):
An exception has been thrown during the rendering of a template (“Zend_Session is currently marked as read-only.”) in “@VisitsSummary/_sparklines.twig” at line 73.
Any ideas?
Mg
same problem on apache and php54
Hi guys,
All of you experiencing this bug, please comment in this issue to make your voice heard!! Goals Overview widget: Zend_Session is currently marked as read-only. · Issue #7274 · matomo-org/piwik · GitHub
Thank you,
Same issue here. Will try to roll back to 2.11.0 for now.
This was posted at github, fixed it for me: https://raw.githubusercontent.com/piwik/piwik/7274/core/Notification/Manager.php
yes, for me too… thx for the link…
Follow github advice! Worked for me!