I'm sorry i forgot to add this.
i use mc 1.7.2 and Forge 10.12.0.1024
and by api url you mean platform url? then it is http://www.technicpack.net/api/modpack/aktion-lanwerk-164
i'm adding liteloader through a modified version.json.
On my other Computer with win 7 64bit it works fine.
the console shows the following log concerning my problem:
[B#439] Starting download of http://dl.liteloader.com/versions/com/mumfrey/liteloader/1.7.2/liteloader-1.7.2.jar, with 3 tries remaining
[B#439] Expected MD5: 66f343354b8417abce1a10d557d2c6e9 Calculated MD5: ab554c21f28fbc4ae9b098bcb5f4cceb
[B#439] Starting download of http://dl.liteloader.com/versions/com/mumfrey/liteloader/1.7.2/liteloader-1.7.2.jar, with 2 tries remaining
[B#439] Expected MD5: 66f343354b8417abce1a10d557d2c6e9 Calculated MD5: ab554c21f28fbc4ae9b098bcb5f4cceb
[B#439] Starting download of http://dl.liteloader.com/versions/com/mumfrey/liteloader/1.7.2/liteloader-1.7.2.jar, with 1 tries remaining
[B#439] Expected MD5: 66f343354b8417abce1a10d557d2c6e9 Calculated MD5: ab554c21f28fbc4ae9b098bcb5f4cceb
The hash calculated by the launcher is correct but the hash he expects is wrong