"In the latest update for GTA V, Ill Gotten Gains Part 2, Rockstar Games strengthened their protections against modding introduced in the first update", they add in a Facebook post. "Included in this was a whopping 3 MB of junk code designed to confuse modders."

They claim the junk code doesn’t confuse modders so much as it simply slows them down, obscuring the commands they used to access directly (to tweak game settings, etc) with reams of crap.

Problem being, that strengthening and "junk code" is affecting all users, slowing down the speed at which GTA V accesses its scripts (ie, the stuff that determines what happens in the game world). The LSPDFR team estimate that some scripts are taking five times longer to complete than before, resulting in sluggish framerates.

A post on Rockstar’s support site raises the issue, and a rep has responded with "We have received reports of lower framerate in GTAV and GTA Online after Title Update 1.28 on PC, and we are looking into these reports now."