You need to check the license configuration for hls vod.
Check if in your httpd.conf (apache configuration file), you have location tag for hls-vod, something like this
Options -Indexes FollowSymLinks
and there HLSFMSDirPath points to the FMS's licenses folder location.
For example, if you have FMS licenses folder at C:\Program Files\Adobe\Flash Media Server 4.5\licenses
Then HLSFMSDirPath must be set to "C:\Program Files\Adobe\Flash Media Server 4.5\" .. It may be relative path as it comes in default apache installation with FMS.
Restart server after that..
Thanks for your suggestion.
The problem was that I used an absolute path in HttpStreamingContentPath and not a relative.
At least in CentOS that caused the problem.