I've just had this problem on my Federation Sci while doing Boldly They Rode. I first tried to equip the freebie EV suit by drag and drop and it wouldn't equip. I then double-clicked the freebie EV suit and my characters costume changed to it, but it was still not equipped (disappeared from inventory though). I'm now stuck…
STO is poorly optimized and does make your computer work harder than it should, however that won't be the cause of your lag. The lag will usually be caused due to one of three things - The server, your connection and/or the abilities being used in the map. This game sort of has a problem with the calculations/procs/stacks.…