Steps to reproduce the issue

After updating to 3.8.11, the frontend login on our website just displays the warning:
The security token did not match. The request was aborted to prevent any security breach. Please try again.
when trying to login.

Expected result

normal log in.

Actual result

Error Message: The security token did not match. The request was aborted to prevent any security breach. Please try again.

System information (as much as possible)

System | Linux 3.13.0-042stab127.2 #1 SMP Thu Jan 4 16:41:44 MSK 2018 x86_64
Build Date | Jul 20 2018 12:58:45
Configure Command | './configure' '--prefix=/opt/plesk/php/7.0' '--bindir=/opt/plesk/php/7.0/bin' '--sbindir=/opt/plesk/php/7.0/sbin' '--libexecdir=/opt/plesk/php/7.0/lib' '--datadir=/opt/plesk/php/7.0/share' '--sysconfdir=/opt/plesk/php/7.0/etc' '--sharedstatedir=/opt/plesk/php/7.0/com' '--localstatedir=/opt/plesk/php/7.0/var' '--libdir=/opt/plesk/php/7.0/lib/x86_64-linux-gnu' '--includedir=/opt/plesk/php/7.0/include' '--infodir=/opt/plesk/php/7.0/share/info' '--mandir=/opt/plesk/php/7.0/share/man' '--build=x86_64-linux-gnu' '--host=x86_64-linux-gnu' '--with-libdir=lib' '--cache-file=../config.cache' '--with-config-file-path=/opt/plesk/php/7.0/etc' '--with-config-file-scan-dir=/opt/plesk/php/7.0/etc/php.d' '--disable-debug' '--without-pear' '--with-pic' '--disable-rpath' '--with-bz2' '--with-freetype-dir=/usr' '--with-png-dir=/usr' '--with-xpm-dir=/usr' '--enable-gd-native-ttf' '--without-gdbm' '--with-gettext' '--with-gmp' '--with-iconv' '--with-jpeg-dir=/usr' '--with-openssl' '--with-pcre-regex' '--with-zlib' '--with-layout=GNU' '--enable-exif' '--enable-ftp' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-sysvmsg' '--with-kerberos' '--enable-calendar' '--with-libxml-dir=/usr' '--enable-xml' '--enable-phpdbg' '--with-enchant=shared,/usr' '--with-system-tzdata' '--with-litespeed' '--enable-pcntl' '--with-imap=shared' '--with-imap-ssl' '--enable-mbstring=shared' '--enable-mbregex' '--with-gd=shared' '--enable-bcmath=shared' '--enable-dba=shared' '--with-db4=/usr' '--with-xmlrpc=shared' '--with-ldap=shared' '--with-ldap-sasl' '--enable-mysqlnd=shared' '--with-mysqli=shared, mysqlnd' '--with-mysql-sock=/var/run/mysqld/mysqld.sock' '--enable-dom=shared' '--with-pgsql=shared' '--with-snmp=shared,/usr' '--enable-soap=shared' '--with-xsl=shared,/usr' '--enable-xmlreader=shared' '--enable-xmlwriter=shared' '--with-curl=shared,/usr' '--enable-pdo=shared' '--with-pdo-odbc=shared, unixODBC,/usr' '--with-pdo-mysql=shared, mysqlnd' '--with-pdo-pgsql=shared,/usr' '--with-pdo-sqlite=shared,/usr' '--with-sqlite3=shared' '--enable-json=shared' '--enable-zip=shared' '--without-readline' '--with-libedit' '--with-pspell=shared' '--enable-phar=shared' '--with-mcrypt=shared,/usr' '--with-tidy=shared,/usr' '--with-unixODBC=shared,/usr' '--enable-fileinfo=shared' '--enable-intl=shared' '--with-icu-dir=/usr' '--enable-sysvmsg=shared' '--enable-sysvshm=shared' '--enable-sysvsem=shared' '--enable-posix=shared' 'build_alias=x86_64-linux-gnu' 'host_alias=x86_64-linux-gnu'
Server API | CGI/FastCGI
Virtual Directory Support | disabled
Configuration File (php.ini) Path | /opt/plesk/php/7.0/etc
Loaded Configuration File | /var/www/vhosts/system/spotteron.net/etc/php.ini
Scan this dir for additional .ini files | /opt/plesk/php/7.0/etc/php.d
Additional .ini files parsed | /opt/plesk/php/7.0/etc/php.d/00-ioncube-loader.ini, /opt/plesk/php/7.0/etc/php.d/10-opcache.ini, /opt/plesk/php/7.0/etc/php.d/20-mysqlnd.ini, /opt/plesk/php/7.0/etc/php.d/50-xdebug.ini, /opt/plesk/php/7.0/etc/php.d/bcmath.ini, /opt/plesk/php/7.0/etc/php.d/curl.ini, /opt/plesk/php/7.0/etc/php.d/dba.ini, /opt/plesk/php/7.0/etc/php.d/dom.ini, /opt/plesk/php/7.0/etc/php.d/enchant.ini, /opt/plesk/php/7.0/etc/php.d/fileinfo.ini, /opt/plesk/php/7.0/etc/php.d/gd.ini, /opt/plesk/php/7.0/etc/php.d/imagick.ini, /opt/plesk/php/7.0/etc/php.d/imap.ini, /opt/plesk/php/7.0/etc/php.d/intl.ini, /opt/plesk/php/7.0/etc/php.d/json.ini, /opt/plesk/php/7.0/etc/php.d/ldap.ini, /opt/plesk/php/7.0/etc/php.d/mbstring.ini, /opt/plesk/php/7.0/etc/php.d/mcrypt.ini, /opt/plesk/php/7.0/etc/php.d/mysqli.ini, /opt/plesk/php/7.0/etc/php.d/odbc.ini, /opt/plesk/php/7.0/etc/php.d/pdo.ini, /opt/plesk/php/7.0/etc/php.d/pdo_mysql.ini, /opt/plesk/php/7.0/etc/php.d/pdo_odbc.ini, /opt/plesk/php/7.0/etc/php.d/pdo_pgsql.ini, /opt/plesk/php/7.0/etc/php.d/pdo_sqlite.ini, /opt/plesk/php/7.0/etc/php.d/pgsql.ini, /opt/plesk/php/7.0/etc/php.d/phar.ini, /opt/plesk/php/7.0/etc/php.d/posix.ini, /opt/plesk/php/7.0/etc/php.d/pspell.ini, /opt/plesk/php/7.0/etc/php.d/redis.ini, /opt/plesk/php/7.0/etc/php.d/snmp.ini, /opt/plesk/php/7.0/etc/php.d/soap.ini, /opt/plesk/php/7.0/etc/php.d/sqlite3.ini, /opt/plesk/php/7.0/etc/php.d/sysvmsg.ini, /opt/plesk/php/7.0/etc/php.d/sysvsem.ini, /opt/plesk/php/7.0/etc/php.d/sysvshm.ini, /opt/plesk/php/7.0/etc/php.d/tidy.ini, /opt/plesk/php/7.0/etc/php.d/xmlreader.ini, /opt/plesk/php/7.0/etc/php.d/xmlrpc.ini, /opt/plesk/php/7.0/etc/php.d/xmlwriter.ini, /opt/plesk/php/7.0/etc/php.d/xsl.ini, /opt/plesk/php/7.0/etc/php.d/zip.ini
PHP API | 20151012
PHP Extension | 20151012
Zend Extension | 320151012
Zend Extension Build | API320151012, NTS
PHP Extension Build | API20151012, NTS
Debug Build | no
Thread Safety | disabled
Zend Signal Handling | disabled
Zend Memory Manager | enabled
Zend Multibyte Support | provided by mbstring
IPv6 Support | enabled
DTrace Support | disabled
Registered PHP Streams | https, ftps, compress.zlib, compress.bzip2, php, file, glob, data, http, ftp, phar, zip
Registered Stream Socket Transports | tcp, udp, unix, udg, ssl, sslv3, tls, tlsv1.0, tlsv1.1, tlsv1.2
Registered Stream Filters | zlib., bzip2., convert.iconv., string.rot13, string.toupper, string.tolower, string.strip_tags, convert., consumed, dechunk, mcrypt., mdecrypt.

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