Export Failed - they dont give much info with that error message...
I know what will work - Move both your DCCashe and DCBackup folders to your desktop.
Make a new folder (empty) on desktop and copy everything except DCMerged from DCBackup into the empty forder - name that new folder like "DCBackup From Game" or something that lets you know what it is.
1. uninstall any previouse copies of the world you want to Export from your game
2. Make empty folder on desktop
3. MOVE DCBackup AND DC Cashe to Desktop
4. COPY all packages (EXCEPT DCMerged) from DCBackup to the new empty folder (name it so you remember what and where it comes from)
5. Place a COPY of that new folder with all the DCBackup "package files" into your GAME's Mod/packages folder
6. Place a copy of that same folder into your Program files\CAW\Packages folder ( you need the CAW framework installed)
7. Start CAW or SuperCAW and Export your World.
This should eliminate the Export Failed problem and incorporate missing content.
Usually - anything you incorporate into your world while in CAW/EIG should remain.
8. Delete the new folders you placed in CAW\Packages and Sims 3\Mods\Packages - delete both of them!
9. MOVE the DCCashe and DCBackup folders from your desktop BACK into The Sims 3 - it will ask if you want to merge (YES) then ask you if you want to REPLACE files (also YES") MERGE!
At this point your Sims 3 is back the way it was before moving DCBackup and DCCashe.
Move or copy the newly exported world into your Downloads folder and install.
NOTE: This way of exporting your world will be much slower... but seems to work
I can't guarantee ALL your CC will come through.
I had the same problem - Reinstalled Origin, The Sims 3 without anything in Downloads folder and NO Mods folders - no package files AT ALL, and CAW on a clean machine - still had "Export Failed" - This helped me. Good Luck and Enjoy Building
Dr. Nonsequitur 2018