rejected does not always mean "rejected by server". I already named the (perhaps, if existing) files above, "rejected" can also mean rejected by your own Oscam client and the configuration and rules made by you.
Easiest way to check = response time: even with the extremly best internet connection, response time from server will always be >6-8ms. So if you got response time about 0-3ms (like teglafal) you can be sure, that request was not answered by cs-server, the rejected-messages was at least LAN (within LAN response time of 1-3ms are possible/normal) but even a ping to any fast server on the internet needs at least 5ms (my provider needs 20ms at minimum), or the Oscam client on your receiver box.
Already explained in Oscam forum: required to run Oscam is only oscam.conf, oscam.user and oscam.server. Here you can make mistakes as well but if its not running reduce your configuration files to that minimum, remove/rename all other oscam.*** files in the config-folder and restart Oscam or your receiver and start again and when its running you can add the other files, which are only for optimization, one by one.