Accidentally deleting instruments from subcategory

Hello all,
In HAlion 6, it’s all too easy to accidentally left click under ‘subcategory’ and press ‘none’. This makes that particular instrument disappear from that subcategory. Is there a work around to this? A way to disable ‘none’? Or at the very least a way to get those instruments back into their respective and rightful subcategories? Perhaps through a factory reset? Is there a factory reset button? Or do I have to reinstall HALion 6?
Thank you.