I've found a
very similar report from 2004, where no solution was found, but
as ‘workaround’ it seemed that using a non-standard port, other higher than port 80, it could help on those cases.
» Just wondering: besides upgrading from HFS 2.3 to 2.4,
try to think what other changes you did on your server. Since HFS worked fine for years, there must be something else that
suddenly is causing this (like for example, an incompatibility with another software, or some other change).
It's known that some applications like Skype, could 'take over' (or grab) port 80/443, thus blocking the normal functioning of HFS, as you can read
HERE. In Windows 10, an "IIS service" is enabled by default (or it could have been re-enabled after a Windows Update), and it could cause the same issue, as you can read
HERE.
• Besides that, if you wish, you can share a debug log by uploading it as attachment here on the forum. To get a debug log, follow
THESE steps, but on step 4 wait until HFS stop responding, and then continue with step 5 onwards.
I can't make any promises or guarantee about fixing this (this only
could be useful to find the origin of the issue, or find a possible workaround, but most of the time, it is not enough to find the source of the error). Remember that without having an EXACT way to reproduce this bug, this could be hard to fix.
At the moment, since Rejetto stopped developing HFS v2.x (now considered obsolete by him), and until an independent fork of the old HFS v2.x branch doesn't arise, I would highly recommend testing his new HFS v3.