Where's "Show all 3rd party plugins" gone???

I'm sure I'm doing something really daft, but...

Been running 7.7.2 on a macbook pro for a while which has been stablie - ish. With the Triode spotify plugin which as everyone says is way, way better than the official one.

Today for some reason I couldn't play another spotify music selection. Using my ipdad version I could see an error message - sadly I didn't note it, but my recollection tells me it told something along the lines of a badly formed message sent to spotify.

I've had a problem with the plugin before, which has been resolved by simply unchecking the appropriate box on the plugin tab, restarting the server, then reselecting it, restarting and all's well.

This time I deselected the box, restarted the server, when I did the Triode spotify option had vanished. Not only so, but there was no "Show all 3rd party plugins" button on the page to enable me to find it again!!! That makes me think it's an issue with the server software itself?

I've tried reinstalling 7.7.2 over the top of the existing install. But no luck, there's still no button to let me find the 3rd party plugins again.

Suggestions please