I tried the SC4Mapper but I have the "invalid folder name" error (I'm on XP, not Vista and of course the folder name *IS* valid). So I tried redering regions manually form downloaded height maps and config.bmps. With some it works, with others it doesn't. I found a solution, which might be applicable in most cases where rendering the region fails. Also people with Vista may find this useful. I had a problem rendering a downloaded height map -- after ctrl+shift+alt+R nothing happens. This is how I fixed it (involes Photoshop but any other image-editing app would do): 1. I opened the jpeg file and adjusted the size as requested (in Photoshop: Image>Image Size> enter in the dialog the width/height in pixels, make sure that the 'Resampling Method' is 'Bicubic'). The size of the height map must be calculated this way: if the region can be filled with a X*Y rectangular grid of small towns (i.e. the config.bmp has dimensions X*Y pixels), the height map must have the size (64*X+1)*(64*Y+1). Thus a grid of 1 large or 4 (2*2) medium or 16(4*4) small towns must have a height map with dimensions 257*257 pixels. I think this is because every pixel corresponds not to a tile on the map but to an edge of a tile. 2a. Convert the image to Grayscale/8 bit depth (Image>Mode>Grayscale>confirm the dialog if any; make sure that Image>Mode>8 bits/channel is checked). Some images *may* look grayscale, but can be in fact in some other color space like indexed color, RGB or whatever. It seems that SC4 expects that the height map image contains only one 8 bit channel -- i.e. pure Gray/8. In Photoshop: in the title bar of the document the image mode is displayed in parentheses . Thus you should have something like: "map.jpg (Gray/8)" in the title bar. 2b. (Optional) Use your image app's native powers for terraforming, changing sea level or whatever as you want. 2c. Save the file as a standart jpeg with max quality -- without any optimizations, loss of quality etc. 3. (Possible) Your config.bmp may also be incorrect. Make sure it contains only pure red, green and blue pixels. These have the following RGB coordinates: (255,0,0); (0,255,0) and (0,0,255) respectively. Also save it as a standart .bmp file with 24 bit color depth. I suggest saving the files as "standartly" as possible. Photoshop is a powerful image processing application and it can open (and save) almost any image type with any encoding/compression etc. but I'm not sure that SC4 can handle some exotic formats correctly. Hope this is useful!