This can happen for a number of reasons :

• If you entered the asset version, try a new search without asset version. If you finally find the kuid with a different version, you will have to modify the config.txt of the dependent asset. Of course it is not sure that the dependent asset works properly with this new version of the dependencie. Some tests in the game will be required to validate that the new version works well.
• Check that this kuid is realy usefull for the dependant asset. The assets designers use copy/past in the config.txt. So quite often some unecessary kuid references are not cleaned in the 'kuid-table' part of the config.txt. If the missing kuid is in the 'kuid-table'  but anywhere else within the config.txt, and if the asset is not scripted, you can probably safely remove this missing kuid from the 'kuid-table' and it will disappear from the missing dependencies list. If the object is scripted, you should  make a test after removing the missing kuid from the 'kuid-table', to check if the script use this reference or not. If everything works well, this means that the object nor the script uses this missing kuid. You can remove it from the 'kuid-table' without risk.
• Unfortunatly many Trainz fan sites are steadily closed, assets are removed from web sites, even at the DLS of N3V/AURAN... More than 10.000 kuid were lost in 2 years !
• Sometimes some asset designer has the missing kuid on his computer but forget to upload it on the DLS or on his web site.
• Even if the database is very comprehensive, it is not exhaustive :
  • About 100 more little web sites are to be further browsed. And new sites are discovered everytime...
  • The database is updated regularly. But of course it can happens that the searched asset is not yet indexed.
  • Somes Trainz fan sites are not easy to identify as Trainz fan sites with download section, or requires to register, but the registration process never achieves, some sites are difficult to use because they use files hosting services that made the files downloading very complicate for a number of files. Some links are dead, some files arre corrupted ...

For those 3 last cases, you should ask to the Trainz fan community via the specialized forums.

To search a kuid you can either choose the Asset search choice of the menu, or use the quick form search in the sidebar, witch is available everywhere in the site.

In both case 3 fields are proposed, matching the 3 parts of the kuid : author id, asset id, asset version.

You can enter :

• only the author id : you will get a list of web sites where assets of this author are proposed;
• the author id and the asset id : you will get a list of sites where any version of this kuid can be found and the links to all pages of those sites where it can be downloaded;
• the full kuid with the asset version : you will get a list of sites where this version of this kuid can be found and the links to all pages of those sites where it can be downloaded. Enter 0 as asset version for full kuid of old type without asset version.

Remember : the author id is the first number of the kuid, the asset id the second numner and the asset version the third number. Only the kuid2 format has the asset version. The old kuid format has only 2 numbers, assuming that the version number is 0.