Hey if any o’ you mappers out there don’t know this…
Be very careful and save often when experimenting with “sphere shapes” in RuneEd. Even just attempting to reform your brush into an “unofficial sphere” will result in a Runtime Error . This error (if’n ye 'aven’t got it yet arrrrgh) will immediately shut down RuneEd 
Original thread: https://lowcaliber.com/eve/forums/a/tpc/f/3886011002/m/2076063834
yup learned that the hard way ole master fisty now I hardly use the sucka.
lol
Never use the default brushes or resize tools.
EVER.
The proper way is to use the square and vertex edit some nice looking shapes that are actually on the grid, unlike everything the resize tools let you do. If you use the tools then you get sloppy badly shaped maps.
Well in all truth to your guys needs. I would suggest using a different modelling program then import them into the map.