Yes there are such terrain files, but it is not really related. This terrain was removed as a part of the Terrain Pack and these files are unused; they should not be there.
I've examined this issue before and found no problems. Just reinstall everything. If the problem persists, please let me know.
BTW I'd gladly publish 1.2, but still waiting for the translations...
EDIT:
version 1.2 has been released.- The mod is Master now.
- New craft: Kitsune-106.
- New Dossier: Dr. Hadriex.
- New mission: Hell Cruise with Dr. Hadriex.
- New units: Dr. Hadriex, Cultist of Spirits, Ancient Sea Ghost.
- New items: Hadriex Gun, Webwear.
- New faction: Children of Aether (logo by Arvidus).
- 6 new events, by Sherris (with minor adjustments).
- New staff input.
- New terrain: Urban Low (by Finnik & Solarius Scorch).
- New Alien Base mapblocks (by Civilian).
- Improved routes on Port TFTD.
- New Spikeboar inventory picture (by Nord).
- New craft system: Fuel Tank.
- MiB base no longer causes point loss.
- Rebalanced Power Mace.
- Psiclone now works like a melee weapon (X-Com Psiclone no longer required and removed).
- Plasma Grenade is now actually plasma.
- Cheaper Pump Action.
- Smartgun now has uniform Auto and Snap range.
- Pepper spray now counts for the Incapacitator commendation.
- Limited Ethereal race research paths.
- Special spiders made more common.
- Fixed Alien Key disappearing on non-related missions.
- Fixed Smart Shotgun Ammo not needing Tritanium.
- Fixed the unblocked free hand on the Flying Drone.
- Minor fixes.
The first point requires a bit of explanation. From now on, the X-Com Files are no longer a normal mod, but a master mod. This means that from the player's point of view, it is now considered a separate X-Com game, just like Piratez. Therefore, instead of enabling it normally, now you need to switch to it just in the same way you would switch from UFO (X-Com 1) to TFTD:
Secondly, if you want to continue a campaign from a previous version, you need to find your xcom1 folder (the one where saves, screenshots and configs are) and rename it to x-com-files.
(On the first launch after this conversion, the game will warn you that there some mods are missing; you can safely ignore this.)