I just downloaded and installed the latest version (3.47-27 64 bit on Vista
x64), replacing my good ol' HTTrack from around 2010.

The new version unexpectedly exits w/o any error message in random
situtations. Sometimes it stops and closes itself when I start to download a
site. Another time it starts but exits when I stop the downloading process. Or
when I just switch to an other application while downloading.

I have an other problem. I replaced my old version because I wasn't able to
make more than 4 connections in the same time. With the same settings the new
version makes 1 or 2 connections to the same site, no more.

Just let me know if I can help with more info to kill these bugs.