missing search labels in contacts after upgrade

📦 Install & Upgrade Help
1

Hi,
I’ve upgraded the backup of my SuiteCRM 7.6.6 Installation to 7.8.3.
When clicking on ‘contacts’ the whole search input fields are missing, It simply shows all the contacts.
In FireBug I get the following error message (which isn’t related to the problem, I think:

NetworkError: 404 Not Found - http://besprechungspause.de/suite_test/cache/jsLanguage/Contacts/en_us.js/?v=eLyOfCssoczYdH1AnPtupw"

Errorlogs show the following:

[Wed Apr 19 13:44:08.554046 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Task::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.554154 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Task::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.563612 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Meeting::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.563724 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Meeting::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.571151 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Meeting::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.571260 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Meeting::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.587525 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Meeting::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.587651 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Meeting::$set_complete in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.604400 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$track_campaign in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.604408 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$launch_wizard in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.604506 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$track_campaign in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.604512 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$launch_wizard in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.608502 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$track_campaign in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.608510 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$launch_wizard in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.612431 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$track_campaign in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.612439 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$launch_wizard in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.616364 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$track_campaign in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.616373 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$launch_wizard in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.616466 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$track_campaign in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui
[Wed Apr 19 13:44:08.616471 2017] [:error] [pid 23102] [client 141.70.27.213:56166] PHP Notice:  Undefined property: Campaign::$launch_wizard in /var/www/besprechungspause.de/public_html/suite_double/sugar/SugarCE622/modules/Home/UnifiedSearch.php on line 179, referer: http://besprechungspause.de/suite_test/index.php?action=ajaxui

I’ve checked all the folder permission as described in upgrade/installation howto.

Is it maybe that this is how SuiteCRM simply looks like after the upgrade? I can see all previous and even custom search filters when clicking on the filter symbol. Is there a way to make them visible all the time like it was in earlier versions?