It is always important to backup your files before importing or updating any assets from the asset store. Likewise it is also important to backup your files before updating your projects between different versions of Unity.
Rotorz Tile System v1.1.3 has just been submitted for approval by the asset store team and will be available for download shortly. This new version is almost identical to v1.1.2 except that it a) works with Unity 4 and b) has a different brush creation window.
- Unity 3.5.x users will be able to upgrade to v1.1.3 or directly to v2.0.0 (when it becomes available in the near future).
- Unity 4.x users will be able to upgrade from v1.1.3 to v2.0.0.
Please contact us if you have any questions regarding this.