Unable to send the cookie. Maximum number of cookies would be exceeded

[gputignano]

It happens on a fresh magento v2.1.3 installation via composer.
Apache/2.4.23 (Win32) OpenSSL/1.0.2h PHP/5.6.28
Versione del client del database: libmysql - mysqlnd 5.0.11-dev - 20120503
Estensione PHP: mysqli Documentazione
Versione PHP: 5.6.28

When I try to access admin area I get:

There has been an error processing your request
Exception printing is disabled by default for security reasons.
Error log record number: 1761570144

In var/report I get:

a:4:{i:0;s:71:"Unable to send the cookie. Maximum number of cookies would be exceeded.";i:1;s:5183:"#0 C:\xampp\htdocs\magento2\vendor\magento\framework\Stdlib\Cookie\PhpCookieManager.php(116): Magento\Framework\Stdlib\Cookie\PhpCookieManager->checkAbilityToSendCookie('admin', 'luov8matk9kh36a...')
#1 C:\xampp\htdocs\magento2\vendor\magento\framework\Stdlib\Cookie\PhpCookieManager.php(98): Magento\Framework\Stdlib\Cookie\PhpCookieManager->setCookie('admin', 'luov8matk9kh36a...', Array)
#2 C:\xampp\htdocs\magento2\vendor\magento\module-backend\Model\Auth\Session.php(177): Magento\Framework\Stdlib\Cookie\PhpCookieManager->setPublicCookie('admin', 'luov8matk9kh36a...', Object(Magento\Framework\Stdlib\Cookie\PublicCookieMetadata))
#3 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(74): Magento\Backend\Model\Auth\Session->prolong()
#4 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Chain\Chain.php(70): Magento\Backend\Model\Auth\Session\Interceptor->___callParent('prolong', Array)
#5 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Backend...', 'prolong', Object(Magento\Backend\Model\Auth\Session\Interceptor), Array, 'security_admin_...')
#6 C:\xampp\htdocs\magento2\vendor\magento\module-security\Model\Plugin\AuthSession.php(68): Magento\Backend\Model\Auth\Session\Interceptor->Magento\Framework\Interception\{closure}()
#7 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(142): Magento\Security\Model\Plugin\AuthSession->aroundProlong(Object(Magento\Backend\Model\Auth\Session\Interceptor), Object(Closure))
#8 C:\xampp\htdocs\magento2\var\generation\Magento\Backend\Model\Auth\Session\Interceptor.php(65): Magento\Backend\Model\Auth\Session\Interceptor->___callPlugins('prolong', Array, Array)
#9 C:\xampp\htdocs\magento2\vendor\magento\module-backend\App\Action\Plugin\Authentication.php(127): Magento\Backend\Model\Auth\Session\Interceptor->prolong()
#10 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Chain\Chain.php(67): Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#11 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Backend...', 'dispatch', Object(Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor), Array, 'adminMassaction...')
#12 C:\xampp\htdocs\magento2\vendor\magento\module-backend\App\Action\Plugin\MassactionKey.php(33): Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#13 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(142): Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#14 C:\xampp\htdocs\magento2\var\generation\Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor.php(39): Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->___callPlugins('dispatch', Array, Array)
#15 C:\xampp\htdocs\magento2\vendor\magento\framework\App\FrontController.php(55): Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#16 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(74): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#17 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Chain\Chain.php(70): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#18 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#19 C:\xampp\htdocs\magento2\vendor\magento\framework\Module\Plugin\DbStatusValidator.php(69): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#20 C:\xampp\htdocs\magento2\vendor\magento\framework\Interception\Interceptor.php(142): Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#21 C:\xampp\htdocs\magento2\var\generation\Magento\Framework\App\FrontController\Interceptor.php(26): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, Array)
#22 C:\xampp\htdocs\magento2\vendor\magento\framework\App\Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#23 C:\xampp\htdocs\magento2\vendor\magento\framework\App\Bootstrap.php(258): Magento\Framework\App\Http->launch()
#24 C:\xampp\htdocs\magento2\index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#25 {main}";s:3:"url";s:103:"/magento2/admin/admin/index/index/key/fc129c8ab7fb7cc037a101891fc63ed0635cbee765a836e40c90d7164ab90874/";s:11:"script_name";s:19:"/magento2/index.php";}

[veloraven]

@gputignano thank you for your feedback.
Magento does not support the operating system you've listed. Please confirm that you can reproduce this issue on a supported platform. For an overview of supported technologies, see System Requirements.

[magnetic5355]

@veloraven - even though @gputignano is using incompatible OS, it would not make a difference in this error. I also routinely see this error logged on debian, php7 and nginx.

[southerncomputer]

https://github.com/magento/magento2/blob/2.0.0/lib/internal/Magento/Framework/Stdlib/Cookie/PhpCookieManager.php#L29

delete your cookies for that hostname or increase 50 to a larger number! too many stale cookies for cookie manager!

[OZZlE]

Still getting this exception with the "fix" 50 there..

[OZZlE]

I am thinking "User Agent" is a browser and not the server side implementation..

"At any time, the user agent MAY "remove excess cookies" from the
cookie store if the number of cookies sharing a domain field exceeds
some implementation-defined upper bound (such as 50 cookies)." https://tools.ietf.org/html/rfc6265

Also it doesn't say that when the limit is reached that the site should crash with a fatal error :D

[mark-netalico]

Is there any plan to fix this? I'm definitely seeing this issue.

[matthewhaworth]

We've had this issue too, it's been exceeding 100 cookies for me. It appears to be duplicating some, which I wasn't even sure was actually possible..

[iancassidyweb]

Any update on this issue?

We're seeing the following error which is producing an error report and causing the site to fall over

"There has been an error processing your request
Unable to send the cookie. Maximum number of cookies would be exceeded."

It looks like the MAX_NUM_COOKIES was raised to 50 (used to be 20) as part of:
c945dbe

However, would it not make more sense for it to be a system configuration value? Which gives merchants greater control over their website?