I have this error log from version 5.0.1

Error: Call to undefined method IPS\forums\Topic::TopicCount() in system/Theme/Theme.php(891) : eval()'d code:1402
Stack trace:
#0 system/Theme/SandboxedTemplate.php(61): IPS\Theme\class_forums_front_index->forumRow()
#1 system/Theme/Theme.php(891) : eval()'d code(1875): IPS\Theme\_SandboxedTemplate->__call()
#2 system/Theme/SandboxedTemplate.php(61): IPS\Theme\class_forums_front_index->index()
#3 applications/forums/modules/front/forums/index.php(225): IPS\Theme\_SandboxedTemplate->__call()
#4 system/Dispatcher/Controller.php(118): IPS\forums\modules\front\forums\_index->manage()
#5 applications/forums/modules/front/forums/index.php(52): IPS\Dispatcher\_Controller->execute()
#6 system/Dispatcher/Dispatcher.php(153): IPS\forums\modules\front\forums\_index->execute()
#7 index.php(13): IPS\_Dispatcher->run()
#8 {main}

#0 system/Theme/SandboxedTemplate.php(71): IPS\_Log::log()
#1 system/Theme/Theme.php(891) : eval()'d code(1875): IPS\Theme\_SandboxedTemplate->__call()
#2 system/Theme/SandboxedTemplate.php(61): IPS\Theme\class_forums_front_index->index()
#3 applications/forums/modules/front/forums/index.php(225): IPS\Theme\_SandboxedTemplate->__call()
#4 system/Dispatcher/Controller.php(118): IPS\forums\modules\front\forums\_index->manage()
#5 applications/forums/modules/front/forums/index.php(52): IPS\Dispatcher\_Controller->execute()
#6 system/Dispatcher/Dispatcher.php(153): IPS\forums\modules\front\forums\_index->execute()
#7 index.php(13): IPS\_Dispatcher->run()
#8 {main}