The error handler says "MenuScreen_Options+$0062", I believe the instruction is going to be a word move to or from the address $FFFFF7B9, it'll be a direct write/read as none of the address registers have this address. Likewise, this instruction is going to be just a few lines below "clr.w ($FFFFF7F0).w", you just barely didn't show us enough of the routine to see the instruction responsible, it's... just right below the screenshot, just barely missed it. Take a screenshot of the instructions further down and we'll point out which one. I think you have roughly 8-C bytes left to reach it. Basically... you cannot perform word operations on odd addresses because of the way the CPU handles the 16-bit BUS. I haven't used SonED in quite a long time, so I don't remember if it does. But make sure you are in "layout edit" mode to ensure that when you do press the "space" bar, it will affect the chunk you're hovering over, and not an object or something silly.