I just loaded up my model into TF2, selected all the files and when I went to preview got this,

Compiling TGA: materialsrc\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_1_color.tga
- Compilation successful.
Compiling VTF: materials\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_1_color.vtf
input file: c:/program files/steam/steamapps/dark_omega27/sourcesdk_content/tf/materialsrc/models/workshop/player/items/heavy/lincoln_preview2/lincoln_preview2_1_color
output directory: c:/program files/steam/steamapps/common/team fortress 2/tf/materials/models\workshop\player\items\heavy\lincoln_preview2
config file c:/program files/steam/steamapps/dark_omega27/sourcesdk_content/tf/materialsrc/models/workshop/player/items/heavy/lincoln_preview2/lincoln_preview2_1_color.txt
SUCCESS: Vtf file created
- Compilation successful.
Compiling VMT: materials\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_1.vmt
CTargetVMT::Compile OK! - materials\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_1.vmt
Compiling TGA: materialsrc\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_color.tga
- Compilation successful.
Compiling VTF: materials\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_1_color.vtf
input file: c:/program files/steam/steamapps/dark_omega27/sourcesdk_content/tf/materialsrc/models/workshop/player/items/heavy/lincoln_preview2/lincoln_preview2_1_color
output directory: c:/program files/steam/steamapps/common/team fortress 2/tf/materials/models\workshop\player\items\heavy\lincoln_preview2
config file c:/program files/steam/steamapps/dark_omega27/sourcesdk_content/tf/materialsrc/models/workshop/player/items/heavy/lincoln_preview2/lincoln_preview2_1_color.txt
SUCCESS: c:/program files/steam/steamapps/common/team fortress 2/tf/materials/models\workshop\player\items\heavy\lincoln_preview2/lincoln_preview2_1_color.vtf is up-to-date
- Compilation successful.
Compiling VMT: materials\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.vmt
CTargetVMT::Compile OK! - materials\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.vmt
Compiling DMX: models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.dmx
- Compilation successful.
Compiling DMX: models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_lod1.dmx
- Compilation successful.
Compiling DMX: models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_lod2.dmx
- Compilation successful.
Compiling QC: models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.qc
- Compilation successful.
Compiling MDL: models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.mdl
all paths:c:\program files\steam\steamapps\common\team fortress 2\tf\custom\eve hud\;c:\program files\steam\steamapps\common\team fortress 2\tf\custom\my_custom_stuff\;c:\program files\steam\steamapps\common\team fortress 2\tf\tf2_textures.vpk;c:\program files\steam\steamapps\common\team fortress 2\tf\tf2_sound_vo_english.vpk;c:\program files\steam\steamapps\common\team fortress 2\tf\tf2_sound_misc.vpk;c:\program files\steam\steamapps\common\team fortress 2\tf\tf2_misc.vpk;c:\program files\steam\steamapps\common\team fortress 2\hl2\hl2_textures.vpk;c:\program files\steam\steamapps\common\team fortress 2\hl2\hl2_sound_vo_english.vpk;c:\program files\steam\steamapps\common\team fortress 2\hl2\hl2_sound_misc.vpk;c:\program files\steam\steamapps\common\team fortress 2\hl2\hl2_misc.vpk;c:\program files\steam\steamapps\common\team fortress 2\tf\;c:\program files\steam\steamapps\common\team fortress 2\hl2\;c:\program files\steam\steamapps\common\team fortress 2\tf\download\
qdir: "c:\program files\steam\steamapps\dark_omega27\sourcesdk_content\tf\models\workshop\player\items\heavy\lincoln_preview2\"
gamedir: "c:\program files\steam\steamapps\common\team fortress 2\tf\"
g_path: "c:\program files\steam\steamapps\dark_omega27\sourcesdk_content\tf\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.qc"
Building binary model files...
Working on "lincoln_preview2.qc"
DMX Model c:\program files\steam\steamapps\dark_omega27\sourcesdk_content\tf\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.dmx
DMX Model c:\program files\steam\steamapps\dark_omega27\sourcesdk_content\tf\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_lod1.dmx
DMX Model c:\program files\steam\steamapps\dark_omega27\sourcesdk_content\tf\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2_lod2.dmx
ERROR: unknown attachment link 'bip_head'
ERROR: Aborted Processing on 'workshop/player/items/heavy/lincoln_preview2/lincoln_preview2.mdl'
CTargetMDL::Compile Failed - c:\program files\steam\steamapps\common\team fortress 2\tf\models\workshop\player\items\heavy\lincoln_preview2\lincoln_preview2.mdl
WARNING: CTarg

Does anyone know what the problem is, I understand it a bip_head not being recognises,

ERROR: unknown attachment link 'bip_head'

But it should be, help.
Thanks