If it is, in fact, perfectly ok and no missing dependencies i.e. no red exclamations, red or yellow puzzle pieces shown in CMP next to it, then the problem is likely a missing mesh-table in the config.txt file.
shadow
{
mesh "sd402_shadow/sd402_shadow.im"
}
}
category-region-0 "US"
category-region-1 "CA"
category-era-0 "1960s"
category-era-1 "1970s"
category-era-2 "1980s"
category-era-3 "1990s"
category-era-4 "2000s"
category-class "AL"
smoke_shade 0.3
smoke_random 2.5
smoke_slowlife 6
smoke_fastlife 0.8
smoke_height 1.7
smoke_fastspeed 1.6
description "
From 1972 to 1986 EMD produced this 3000 HP locomotive. They produced a total of 3,957 units which were used by almost all Class 1 railroads at the time.
Models and Textures by Deleted - Copyright 2004-2008
"
asset-filename "sd402"
author "Deleted"
contact-email "Deleted"
contact-website "Deleted"
license "
May not be used in or referenced from any commerical content.
All logos and registered trademarks are property of their copyright holders.
Author of this content takes no responsibility for any damage that this content may cause from it's use.
Content is provided as is.