The names come up as TXT_KEY_...
This means that one of the text keys in your mod duplicates one that's already in the game. This is very common with custom civs, since they'll often add a city name that'll be identical to one the game already has in its lists. The Database.log file should tell you which key is the one conflicting.
If you don't know where the logfiles are, or you haven't turned them on yet, then go do that first. In Windows 7 it'll be in My Documents/My Games/Sid Meier's Civilization V/Logs, and a similar place for other OSs. To turn on logging, go into your game's config.ini file (in the same place as the Logs directory) and turn "LoggingEnabled = 0" to a 1.
What happens is, the game ignores the
entire XML file containing the second conflicting entry (which is yours). If you put those text keys in the same file as some of your other XML changes, then all of them are being lost.
As for the VFS question he mentioned, this is one area where Kael's guide is very out of date. If you're adding any kind of custom artwork (like new icons), then the default will NOT work and you need to change the VFS setting on that file by hand. In ModBuddy, right-click on the file and select Properties. The bottom line will be "Import into VFS", defaulting to false. You need to set it to True for:
> New artwork files (.DDS)
> Non-GameData XML, SQL, or Lua files that replace one of the game's existing files in its entirety (mainly for UI changes)
> Lua files that are intended to be included in other files, instead of tied to an event directly.
Basically, if you're loading the file through an OnModActivated or InGameUIAddin command, then you leave VFS set to False, and for everything else you set it to True.