Deleting any function from UMG crashes editor.

BP correct? If so, try right clicking the UMG and validating asset and dependencies, fixup redirectors for the folder its in, resave all assets (right click folder and resave all). See if that helps. I had this issue before, but don’t exactly remember how I fixed it. It was something along these lines.

Edit: If this fails, check if you have any drivers to update. I’d first check for GPU drivers.