I get a TCP socket error when I open two instances of the toolkit (expected as the first instance already has the socket) but I don't recall seeing that specific error. I've never seen it do anything bad, but unless you're running two instances to compare profiles or copy things between profiles, there's really no need IMO. In fact, when I launch a second copy of the toolkit, I get a popup asking me if I'm really sure I wanna open a new copy.
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