Which xtra file does the projector ask for?
The solution I prefer for creating a projector is to:
1) Choose File > Publish Settings
2) Click on the File tab
3) Select the Exclude All Xtras checkbox
4) Click Publish
This will create a folder named Xtras alongside your projector.
If any xtra files are missing, you can place a copy of the missing xtra in this Xtras folder.
Does this help you solve the problem?