Headless Server 0.15.1 CRC-Error

[oNcLe]

Hello,

i bought a server at nitrado.net.
i installed factorio_headless_x64_0.15.1.tar to it.
My Game is listed in the Multiplayer list "oNcLe's Game" it shows Mods: base 0.15.1
but if i try to connect i get the following Error:
"Core mod CRC check failed! Core game data does not match expected content."
There are no mods serverside and no mods on my client.

I tried using steam 0.15.x beta and standalone client 0.15.1

edit: more details tomorrow going to bed now.

Greetings oNcLe