Fatal error: PHP error in file /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/util/DLDBUtil.class.php (234): Non-static method DLDBUtil::getAllowedKat() should not be called statically

Information:

error message: PHP error in file /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/util/DLDBUtil.class.php (234): Non-static method DLDBUtil::getAllowedKat() should not be called statically
error code: 0
file: /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/system/WCF.class.php (255)
php version: 5.4.45
wcf version: 1.0.11 pl 4 (Horizon)
date: Mon, 18 Nov 2019 14:34:38 +0000
request: /forum/index.php?page=DownloadDB&s=67da73f72aa86f0696e1eb7fe355cdecb8cbdf47
referer:

Stacktrace:

#0 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/util/DLDBUtil.class.php(234): WCF::handleError(2048, 'Non-static meth...', '/homepages/3/d5...', 234, Array)
#1 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/util/DLDBUtil.class.php(234): DLDBUtil::getAllowedKat()
#2 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/page/DownloadDBPage.class.php(100): DLDBUtil::countDatas()
#3 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/page/DownloadDBPage.class.php(39): DownloadDBPage->makeStats()
#4 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/page/AbstractPage.class.php(74): DownloadDBPage->readData()
#5 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/page/DownloadDBPage.class.php(92): AbstractPage->show()
#6 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/page/AbstractPage.class.php(36): DownloadDBPage->show()
#7 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/util/RequestHandler.class.php(63): AbstractPage->__construct()
#8 /homepages/3/d507821608/htdocs/joomla/forum/wcf/lib/util/RequestHandler.class.php(91): RequestHandler->__construct('DownloadDB', Array, 'page')
#9 /homepages/3/d507821608/htdocs/joomla/forum/index.php(8): RequestHandler::handle(Array)
#10 {main}