Error after upgrading from Pydio 7 to 8

I did an “apt-get install --only-upgrade pydio” to upgrade to the newest version, now I am getting this error message when trying to use the site

Parse error: syntax error, unexpected ‘function’ (T_FUNCTION), expecting identifier (T_STRING) or \ (T_NS_SEPARATOR) in /usr/share/pydio/core/vendor/zendframework/zend-diactoros/src/functions/marshal_headers_from_sapi.php on line 10

Not sure if there is a PHP error.
My PHP version is below
PHP 7.1.1-1+deb.sury.org~trusty+1 (cli) (built: Jan 20 2017 09:43:29) ( NTS )
Copyright © 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright © 1998-2017 Zend Technologies
with Zend OPcache v7.1.1-1+deb.sury.org~trusty+1, Copyright © 1999-2017, by Zend Technologies

Hi @Xphacter,
Did you try to clean plugin cache: rm -rf /var/lib/pydio/data/cache/plugins_* (or plugin_*)

Yes. I did both. Nothing changed

In my opinion, it seems that the error is PHP related because it is having trouble parsing the function when it looks like it was expecting a string or NS Separator.