For those that use Steam, there is an issue on Valve's end and this has nothing to do with T:ANE or Trainz in that matter, or even your video card drivers as others have thought in various tech forums.https://www.reddit.com/r/Steam/comments/6p9o48/is_the_steam_app_laggin_for_anyone_else_both_of/The fix is to clear the cache files in Steam and disabling the web-helper. I recommend reading the how-to at the top of the link.