I access any account after install foreach error

After installing OCS.
Error Log shows this error messages.
I cannot accesss the login account
WTF!!!

Here the error log contents:

[21-Feb-2018 08:18:08 Etc/GMT] ocs2 has produced an error
Message: WARNING: Invalid argument supplied for foreach()
In file: /home/webuser/public_html/conference/classes/install/Install.inc.php
At line: 117
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
[21-Feb-2018 08:18:08 Etc/GMT] ocs2 has produced an error
Message: WARNING: Invalid argument supplied for foreach()
In file: /home/webuser/public_html/conference/classes/install/Install.inc.php
At line: 117
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
[21-Feb-2018 08:18:12 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘a’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘em’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘strong’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘cite’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘code’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘ul’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘ol’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘li’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘dl’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘dt’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘dd’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘b’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘i’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘u’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘sup’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘sub’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘br’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log
[21-Feb-2018 08:18:13 Etc/GMT] ocs2 has produced an error
Message: USER WARNING: Attribute ‘’ in element ‘p’ not supported (for information on implementing this, see the support forums)
In file: /home/webuser/public_html/conference/lib/pkp/lib/htmlpurifier/library/HTMLPurifier/HTMLDefinition.php
At line: 324
Stacktrace:
Server info:
OS: Linux
PHP Version: 5.6.31
Apache Version: N/A
DB Driver: mysql
DB server version: 5.6.36-82.0-log