It is possible that your build is missing the ShalltyUtils plugin, or you have an older version of this plugin, not its updated version (Currently version 1.3). I disabled KK_ShalltyUtils in KKManager and this option disappeared for me too.
I would advise you to install this plugin, as many authors make their scenes using this plugin and its absence can affect the performance of the scene up to its complete breakdown.
I will leave a link with an archive to the plugin for you. It will also contain 2 more plugins in case when you launch CharaStudio you get an error about old versions of plugins.
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Also do not forget to make a backup copy of your files before installation.