Sorry for the late reply, this has no effect on the grass bug. I have just reinstalled all of STEP Extended because of another bug where CTDs were occurring during transitions through Whiterun front gate and Dragonsreach front doors. Both of these bugs, the grass and the CTDs, still seem to occur. The CTDs are not occurring frequently and so far only occur in Whiterun. Very puzzling any advice on where to look for clues on the cause would be greatly appreciated. Thanks for the help.