I have been coding and constructing a map for over three weeks now and I was continuing it today when I noticed that there was a color scheme bug on the outside floor textures. So I tried to put a light_grid_volume box around my map to try and fix it. I did so and went to click the hollow out button at the top. Apparently I pressed CSG subtract and noticing my mistake I clicked on the toggle to hollow out the box. I switched windows for a short while to come back to my radiant frozen. So I stopped the program in the Launcher's task manager and restarted it. I loaded the map file and now EVERYTHING is basically deleted except a few models and spawners. All my buildings are deleted and those probably took the longest. I have been modeling it after a few places I know of and wanted the detail to be exact. I freaked out and tried clicking CTRL-Z (undo) but to no avail. The map had already been saved and the undos don't work anymore. In retrospect, I hadn't compiled the map and still have the full map but I don't believe I can edit it anymore. I tried to see if I could load a backup save that Radiant usually creates but it didn't make one. Is there a way to edit an already compiled map without the map file? Or do I have to work with the map file that I have now with my entire map deleted?

Without a backup your progress will have been lost. You should check carefully there is no backup, usually called 'mymap.bak' just rename the extension. Otherwise its a harsh lesson of how important manual backups are.

Check out Assembla for the future.

Free SVN hosting, been using it for years now with all of my CoD projects (I have one SVN depot for each CoD game so all the files fall properly into installation folder for each game). Doesn't just host your files for you but also versioning so you can always sync back should something completely break you're working on. Can also invite other people to your depot to collaborate and keep things tidy so everyone has the same files.

Should be a standard practice for every modder, even (and especially) if you just make maps.

Thanks everyone. I began the reconstruction of my map. Also if anyone was wanting to find a quick way to backup your map without manually having to copy and paste the .map file, you may want to read on.

Just create a batch file in Notepad and add these lines into it:

xcopy /s "C:\(WHERE THE ORIGINAL .MAP FILE IS)" "C:\(WHERE YOU WANT THE COPY TO GO)"

If you want to overwrite a file without prompt, just add /y to the end for it to look like:

xcopy /s "C:\(WHERE THE ORIGINAL .MAP FILE IS)" "C:\(WHERE YOU WANT THE COPY TO GO)" /y