Grab an invisible wall somewhat larger than the area you plan on working on (the bigger the better). Drop it in and set the Y value to your floor's Y value. Set the 'R' rotation to -90. Reposition it in 3d so the control box is outside your Edit Distance and you should not fall through the floor any more. Don't forget to remove it before publishing of course if it happens to block anything you need to access in the quest. Otherwise, there's no reason not to leave it in there in case you need to edit stuff further.
If a tree falls in a virtual forest, how big is the sound file?
Please review my "Finger of God" campaign: NWS-DPJMGYJGV
Quest #1: NW-DS24FX4BC - Cragsford
Quest #2: NW-DTPUNXUAB - Mine's Mine
Quest #3: NW-DIPZQ7CMS - Are We There Yeti?
Quest #4: NW-DSCFDT5WS - Finger of God
Comments
The Lost Keep NW-DS1XBAK7D An experiment Daily Foundry
The Ruined Temple NW-DBHC7MUBL Latest and last one Daily Foundry