Making everything back to worldspawn was a bad idea. If you mess something up, like enter an invalid key to many entities, press L to open Entity list, click on the small arrow next to map name, go through the entities, select the invalid keys, and press 'Delete Key'.
What you did was change several entities into several worldspawns

. You can either delete the extra worldspawns (in list select the ones that don't contain most of map) and recreate what you lost (a few entities and some patch arches, should be easy) or if you have a version before messing up (check for autosave file, or in snapshots subfolder) you could start from there. Also, there is undo, and saving new map versions as new files. The multiple world entities seem to be the cause of the error.
Also you seem to have
a func_door 2 func_doors overlapping structural brushes, and have used 'hollow' to create the largest room, causing the walls to overlap.
You should also make all brushes that don't seal the map from void detail with Ctrl+M when those are selected. There is a nice guide to VIS in one of the stickies...