Error with attachment

Versions
openSUSE Tumbleweed
Kopano 8.4.0~344-77.1
WebApp 3.3.0.600-429.1
Apache 2.4.25-5.1
PHP 7.1.4-1.1

Problem
After attachment upload (WebApp) I always get an “HTTP 500 Internal Server Error”.

Apache error log:
[Thu Apr 27 18:50:04.797864 2017] [php7:error] [pid 8772] [client xxx:64308] PHP Fatal error: Uncaught Error: Using $this when not in object context in /usr/share/kopano-webapp/server/includes/upload_attachment.php:81
Stack trace:
#0 /usr/share/kopano-webapp/server/includes/load.php(39): include()
#1 /usr/share/kopano-webapp/index.php(167): include(’/usr/share/kopa…’)
#2 {main}
thrown in /usr/share/kopano-webapp/server/includes/upload_attachment.php on line 81, referer: https://xxx/webapp/

Workaround (disable plugin hook)
Remove following part in /usr/share/kopano-webapp/server/includes/upload_attachment.php

                                    $GLOBALS['PluginManager']->triggerHook('server.upload_attachment.upload', array(
                                            'moduleObject' =>& $this,
                                            'tmpname'  => $attachment_state->getAttachmentPath($attachid),
                                            'name' => $filename,
                                            'size' => $FILE['size'],
                                            'sourcetype' => $sourcetype,
                                            'returnfiles' =>& $returnfiles
                                    ));

Help?
I’m not a php expert and don’t relay know what $this means in that context. Could someone help me to reenable the plugin hook?

Could be related:
https://jira.kopano.io/browse/KW-1291

I’ve added your case in the ticket, so that will be checked soon.

Hi Marty

That is exactly the issue, thanks for fixing it :-).

Regards