Rolling Line has grown a lot over the last 2+ years, and so has the modding system.
"QuickMods" were originally a hasty solution to the communities request for modding trains with custom models.
This system was never actually meant to be a full modding system, just a quick solution (hence the name "QuickMods").

Recently Rolling Line got a big modding upgrade in the form of "prop mods" which uses a brand new in-game UI and handles mod sharing through the Steam Workshop.

At some stage i hope to bring train modding to the new system (e.g. in-game model importing, preview model, more advanced options, etc) but this will be a while away at least.
So in the meantime, you can now go through a simple process to "convert" your old legacy mods into the new system so they can make use of all of the new features.

After converting a QuickMod/QuickTerrain mod to the new system, you can:

• Give it a thumbnail
  
• Give it tags
  
• Upload it to the Steam Workshop
  
• Include it in mod groups
  
• Package it inside save files when uploading to the workshop
  
• Browse it in the tiled mod list in the in-game drawers

Once converted, a copy of the mod will be made in the "mods" folder, instead of the original "quickMod" or "quickTerrain" folder.

Before moving on to the conversion process, you can read more about creating legacy QuickMods in this guide:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1789707835

Once you have a QuickMod ready and in your "Rolling Line/Modding/QuickMods" folder, you can convert it to the new system in-game.

For this example, this is what your "quickMod" folder should roughly look like:
(I am going to use the "Rift Valley Railways U26C" as an example, the other folders dont matter)



And then the mods folder should look like this (a typical QuickMod):



Once you are sure that the QuickMod you want to convert is ready to go, launch the game and go to the modding manager
(Pause menu -> Modding)



From here you can select the category drop-down-list and choose "Legacy QuickMod":



Now click "Add new" to create a new mod.



You'll be asked to give it a name, then greeted with this view:



On this menu you can set up all the standard modding features like tags and adding a thumbnail, but the important part is the "Select a QuickMod" list.

This list will show all of the legacy QuickMods that are installed.

You can click on them to spawn them (e.g. for taking a thumbnail) but most importantly you can click on the checkbox next to the name to choose which QuickMod will be used.

For this example I selected the "Rift Valley Railways U26C":



Make sure you remember to select the mod you want to convert from the list! Otherwise the new mod will be empty.

Once you have the correct mod selected, click "Save" and you will be taken back to the modding manager menu, with your new mod added!



And it's as simple as that!

Now that you have added a new mod (with the legacy QuickMod selected) you can treat this new mod just like any other. You can click on it to spawn in the train, or upload it to the steam workshop:



You can also now access this new mod in the mods drawer (same place where you spawn in prop mods):



The files for the QuickMod (e.g. models and textures) have now been copied into the standard "mods" folder (Rolling Line/Modding/Mods) and should look like this:



Remember, these are the files linked to the new mod!
If you edit the old files back in the "QuickMod" folder the changes will not show up!

If you want to make changes to the mod make sure you are editing the new files ("mods" folder), not the old files ("quickMods" folder).

QuickTerrain follows exactly the same process as QuickMods.

Simply make sure your chosen QuickTerrain is in the right folder:
(Rolling Line/Modding/QuickTerrain)



Then go into the modding manager, select "Legacy QuickTerrain" and add a new mod:



From here you can set things up exactly as you would with a QuickMod, except instead of choosing a QuickMod from the list, you instead choose a QuickTerrain:



And it's as simple as that!

You can now upload your QuickTerrain to the workshop, or even package it inside a layout when you upload it.