> $ /usr/bin/httrack --disable-security-limits
> --max-rate=0  -%c3000 --continue -s0
> results in:
> Floating point exception (core dumped)

Wow, -%c3000 requests "3000 connections per second", which is way beyond any
reasonable value.

(The option value should be rejected, actually)

Try to use a more reasonable value (such as -%c10) - and beware not to
overload the remote server; using --disable-security-limits is quite dangerous
if you are not absolutely sure of what you are doing (it may bring the server
to its knees, and even cause denial of service).