Rendering on windows fails without any feedback

When I'm using command `aglio -i input.md -o output.html` aglio sometimes (quite often) does not produce any output file and does not send any stacktrace or error message to the console. I suppose the rendering fails because or some mistakes in input file, however, I can't even locate them. `--verbose` option does not help either: aglio writes to console "Loading default theme" and then finishes without any output

Machine:
Windows 7
Python 2.7