Fatal error: PHP error in file /usr/www/users/mykhao/web/wcf/lib/util/DLDBUtil.class.php (234): Non-static method DLDBUtil::getAllowedKat() should not be called statically

Information:

error message: PHP error in file /usr/www/users/mykhao/web/wcf/lib/util/DLDBUtil.class.php (234): Non-static method DLDBUtil::getAllowedKat() should not be called statically
error code: 0
file: /usr/www/users/mykhao/web/wcf/lib/system/WCF.class.php (255)
php version: 5.4.45
wcf version: 1.0.11 pl 3 (Horizon)
date: Sat, 23 Jul 2016 15:03:25 +0000
request: /index.php?page=DownloadDB
referer:

Stacktrace:

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