Oh, I didn't know that, thanks a lot, I'll check the right file, then.
But anyway, I can't tell when exactly the missing plugins events happen, but I'm just sure it happens pretty often on my computers, whereas I do not install new versions, only adding new plugins...
So, maybe it's a problem with my computers systems ?
There are no rules : sometimes I load my MPT and I can see that many plugins have disappeared from the list...Weird...