DispGen "Unable to open heightmap image"

Okay, this is seriously ticking me off.

I'm trying to use DispGen to create some terrain. Every tutorial and example simply says "load up the heightmap in bmp, tif, tga, or png" and off you go.

Yet I can not get DispGen to recognize ANY heightmap image I put into it, no matter the format. It says "Unable to open heightmap image" and stops. This happens with bmp, tga, tif, jpg, and gif, no matter what mode they're in (RGB or greyscale), bits per channel (8 or 16), or size (512 or 1024). I can't even get it to open pgm files. I just spent a couple of hours trying as many different combinations as I could.

Using the latest version from Cannonfodder's site.

The only thing I can find on google about it is a post I made a couple of years ago running into the same problem. I ended up using Twister back then, but I can't in this case due to stretching.

Any ideas? Does this program actually work for anyone else?

Rebooted in safe mode, gave DispGen all permissions, restarted. Still can't open any heightmaps. :\

Any ideas what could be blocking its access to files, if that is the problem?

Follow up: Finally just had to use Process Monitor to find out what DispGen was choking on, and apparently the path to the file was too long. It simply truncated the path and that's why it couldn't load anything. :|

Coders, just ...don't do that. There's no reason with modern operating systems. Or if you feel you must do it, at least give a usable warning popup showing what path it's trying to look for.