Zend_Session_Exception on upgrade to php 7.2

My install gives a “Zend_Session_Exception” error upon upgrade to php 7.2, tho it works fine on earlier versions. I have upgraded Omeka to 2.7.1 and updated all of my plugins but cannot figure out what is wrong. I’m on Dreamhost that is removing earlier versions of php on Feb 13. Can anyone help me? Here is the error message:

Omeka has encountered an error
Zend_Session_Exception
The session has already been started. The session id must be set first.

Zend_Session_Exception: The session has already been started. The session id must be set first. in /home/saiic/public_html/ayn/application/libraries/Zend/Session.php:681
Stack trace:
#0 /home/saiic/public_html/ayn/application/libraries/Zend/Session.php(440): Zend_Session::setId(‘cae69509119175a…’)
#1 /home/saiic/public_html/ayn/application/libraries/Zend/Session/Namespace.php(143): Zend_Session::start(true)
#2 /home/saiic/public_html/ayn/application/libraries/Omeka/Form/Element/SessionCsrfToken.php(84): Zend_Session_Namespace->__construct(‘OmekaSessionCsr…’)
#3 /home/saiic/public_html/ayn/application/libraries/Omeka/Form/Element/SessionCsrfToken.php(129): Omeka_Form_Element_SessionCsrfToken->getSession()
#4 /home/saiic/public_html/ayn/application/libraries/Omeka/Form/Element/SessionCsrfToken.php(55): Omeka_Form_Element_SessionCsrfToken->_initToken()
#5 /home/saiic/public_html/ayn/application/libraries/Zend/Form/Element.php(273): Omeka_Form_Element_SessionCsrfToken->init()
#6 /home/saiic/public_html/ayn/application/libraries/Zend/Form.php(1134): Zend_Form_Element->__construct(‘csrf_token’, Array)
#7 /home/saiic/public_html/ayn/application/libraries/Zend/Form.php(1043): Zend_Form->createElement(‘sessionCsrfToke…’, ‘csrf_token’, Array)
#8 /home/saiic/public_html/ayn/application/forms/SessionCsrf.php(22): Zend_Form->addElement(‘sessionCsrfToke…’, ‘csrf_token’)
#9 /home/saiic/public_html/ayn/application/libraries/Zend/Form.php(239): Omeka_Form_SessionCsrf->init()
#10 /home/saiic/public_html/ayn/application/controllers/PluginsController.php(282): Zend_Form->__construct()
#11 /home/saiic/public_html/ayn/application/libraries/Zend/Controller/Action.php(516): PluginsController->browseAction()
#12 /home/saiic/public_html/ayn/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch(‘browseAction’)
#13 /home/saiic/public_html/ayn/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#14 /home/saiic/public_html/ayn/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch()
#15 /home/saiic/public_html/ayn/application/libraries/Zend/Application.php(384): Zend_Application_Bootstrap_Bootstrap->run()
#16 /home/saiic/public_html/ayn/application/libraries/Omeka/Application.php(73): Zend_Application->run()
#17 /home/saiic/public_html/ayn/admin/index.php(28): Omeka_Application->run()
#18 {main}

I don’t think I’ve seen other reports of this problem, and I can’t reproduce it myself…

Maybe your new install of PHP has some different settings that are causing a problem? session.auto_start comes to mind as something that could cause this issue and isn’t normally enabled.