Player Guide/Open Mod Manager

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Open Mod Manager (OMM, also written OpenModMan) is a free mod manager for Windows, originally created by Sedenion (Eri M.) and now maintained as the successor to the older OvGME. It enables and disables DCS mods non-destructively: mods live in a separate folder, OMM stages them into DCS when enabled, and restores the originals when disabled. Nothing in your DCS install is permanently overwritten.

VRS recommends OMM for any mod you install for our server. OMM solves the three problems players hit most often:

DCS updates. DCS patches frequently overwrite files that mods touch. With OMM you flip every mod off before patching, run the update, then flip them back on.
Server integrity checks. OMM lets you disable a mod for one server and re-enable it for another in seconds.
Diagnosing conflicts. When something breaks, you can disable mods one at a time to find the culprit, without reinstalling anything.

The big upgrade over OvGME: VRS publishes two network repositories, one for install-root mods (Auto Starts, etc.) and one for Saved Games mods (the per-aircraft livery packs). Subscribe each in OMM and you get one-click install plus automatic update notifications for the VRS mod packs.

VRSInstall.xml → https://victorromeosierra.com/VRSInstall.xml → goes in a Channel pointed at your DCS install folder.
VRSSavedGames.xml → https://victorromeosierra.com/VRSSavedGames.xml → goes in a Channel pointed at your Saved Games\DCS folder.

The split exists because the two folders live in different roots, and OMM has one Target Destination per Channel. We use two Channels.

Installing OMM

Download OMM 1.3.5 or later from the iquercorb/OpenModMan releases page. Two flavours are offered:

Installer (OpenModMan_1-3-5-x64_setup.exe) - installs OMM like a normal Windows program. Pick this if you want a Start-menu shortcut.
Portable ZIP (OpenModMan_1-3-5-x64_Portable.zip) - unpack anywhere and run OpenModMan.exe directly. No installer.

Either is fine. There are also 32-bit (x86) builds if you need them, but the 64-bit builds are what most players want.

First-run setup

OMM organises mods as Mod Hubs (think "profile" - one per software you mod) containing one or more Mod Channels (one per destination folder). For VRS you'll create one Hub for DCS, with two Channels: one for your DCS install folder, one for your DCS Saved Games folder.

Launch OMM, then:

Click File → New Mod Hub... Give it a name like DCS and pick a folder to store its config (anywhere; e.g. D:\OMM\DCS-Hub).
In the new Hub, click Edit → Add Target Location... (some builds label this Add Mod Channel...).
Fill in the DCS Install channel:

Field	What to enter
Channel name (or "Indicative name")	`DCS Install`.
Target Destination folder	Your DCS install folder, typically: `C:\Program Files\Eagle Dynamics\DCS World` or, for Steam installs: `C:\Program Files (x86)\Steam\steamapps\common\DCSWorld` This is the folder that contains `bin/`, `Mods/`, `Scripts/`, etc. - not your Saved Games folder.
Library folder	Leave the default (a subfolder inside the Channel's home folder). This is where mod packages will be staged.
Backup folder	Leave the default. This is where OMM stores the originals it replaces.

Then add the second Channel: Edit → Add Target Location... again. Fill in the DCS Saved Games channel:

Field	What to enter
Channel name	`DCS Saved Games`.
Target Destination folder	Your DCS Saved Games folder: `C:\Users\<you>\Saved Games\DCS` (or `...\Saved Games\DCS.openbeta` if you run open beta separately - check what DCS actually uses by looking inside `C:\Users\<you>\Saved Games\`). This is the folder that contains `Liveries/`, `Missions/`, `Tracks/`, `Config/`, etc.
Library folder / Backup folder	Leave the defaults, as above.

You only do this once. After that, OMM remembers the Hub and opens straight to the mod list.

Why two channels? DCS stores mods in two different roots: the install folder (where DCS itself lives, e.g. C:\Program Files\Eagle Dynamics\DCS World) and the Saved Games folder (your per-user state, e.g. C:\Users\<you>\Saved Games\DCS). Auto Starts and script edits go in the install root; liveries, kneeboards, and missions go in Saved Games. OMM has one Target Destination per Channel, so one Channel per root.

The install Channel is the one that protects you on patch day - DCS updates rewrite files there, and OMM's backup-and-restore is what makes those mods survive. Saved Games is safe from patches by design, but having OMM manage liveries too gives you auto-updates when VRS publishes new ones.

For the specific VRS packs - what to install where, and where to download them - see Downloads.

Subscribing to the VRS repositories (recommended)

The fastest way to install and stay up-to-date with VRS mod packs. You'll subscribe each Channel to its matching repository.

DCS Install channel → VRSInstall repo:

In your Hub, select the DCS Install Channel.
Click Edit → Target Location properties... and switch to the Network Library tab.
Click Add Network Repository.
Enter:
- Base URL: https://victorromeosierra.com
- Name: VRSInstall (without the .xml extension - OMM appends it automatically)
Click Test to confirm the repository is reachable, then OK to save.

DCS Saved Games channel → VRSSavedGames repo:

Select the DCS Saved Games Channel.
Edit → Target Location properties... → Network Library tab → Add Network Repository.
Enter:
- Base URL: https://victorromeosierra.com
- Name: VRSSavedGames
Test → OK.

Then for each Channel:

Back in the main window, switch to the Network Library tab and click Query. OMM fetches the list of available mods.
Select the packs you want, click Download Selected, and OMM downloads them into your Library.
Enable them in the Library tab as usual.

When VRS publishes an update, the repo's hash for that pack changes; OMM flags an update on its next Query. Click Download again and the new version replaces the old. With the per-aircraft livery split, a typical livery update only re-downloads the affected aircraft's pack (tens to hundreds of MB), not the full 9 GB pile.

Installing a mod manually

If you'd rather skip the repository and download files yourself (or for any one-off mod not in the VRS repo):

Download the mod as a .zip.
Drop the .zip directly into your Channel's Library folder. OMM picks it up automatically; no need to unpack.
In OMM, the mod appears in the Library tab with a status icon. Select it, click Install Selected (or double-click).
Launch DCS. The mod is active.

Important: do not rename the .zip. OMM (and OvGME) require the top-level folder inside the zip to match the filename. VRS_AutoStarts.zip contains a VRS_AutoStarts/ folder; rename the zip and the parse will fail.

Updating and removing mods

To update a mod to a new version (manual install only - subscribed repos handle this automatically):

In OMM, uninstall the existing version (it goes back to "available" status).
Delete the old .zip from your Library folder.
Drop the new .zip in.
Click Install Selected.

To remove a mod entirely:

Uninstall it in OMM.
Delete the .zip from your Library folder.

Never delete a Library .zip while the mod is installed - that strands the modded files in DCS with no clean way to restore the originals. Always uninstall first.

Before a DCS update

DCS patches can rewrite the same files some mods overwrite. The clean routine is:

Open OMM and uninstall everything (select all in the Library tab, click Uninstall Selected).
Quit OMM.
Run the DCS updater and let it finish.
Re-open OMM and re-install your mods.

If you forget and run the patch with mods installed, DCS may overwrite OMM's backup with the patched file, and you'll lose the ability to cleanly uninstall the mod later. In that case, delete the mod from OMM, delete the staged file, re-download a fresh copy, and re-install.

Migrating from OvGME

If you were previously using OvGME for VRS mods, do this before configuring OMM, or you'll end up with two managers fighting over the same DCS files:

In OvGME, disable every mod (select all, click "Disable Selected"). OvGME restores the original DCS files.
Verify the install dir looks clean (the Mods/aircraft/*/Cockpit/Scripts/Macro_sequencies.lua files should be back to stock or absent).
Quit OvGME. You can uninstall it if you want, or just leave it idle - it won't conflict as long as nothing is enabled.
Now follow First-run setup above to configure OMM.
Subscribe to the VRS repository or install packs manually as described.

OvGME backups and OMM backups are stored differently and not interchangeable. Don't try to import OvGME's mod list into OMM - just re-download the packs through OMM.

Bringing your existing OvGME library across

If your OvGME Mods folder contains other mods (personal weapon packs, cockpit tweaks, third-party autostarts, etc.), you don't have to re-download all of them. Copy the contents of your OvGME Mods folder into your new OMM Channel's Library folder:

Locate your OMM Channel's Library folder. In OMM, select the Channel and check Edit → Target Location properties → Local Library tab. By default it sits at <HubFolder>\<ChannelName>\Library\.
Copy every mod from your OvGME Mods folder into that Library, except VRS_AutoStarts.zip and Liveries.zip (you'll get those via the VRSInstall and VRSSavedGames repo subscriptions instead - and VRS now publishes liveries as per-aircraft sub-packs, not one monolith) and any OvGME-specific README files.
In OMM's Channel properties → Local Library tab, tick Developer mode. This lets OMM recognise folder-form mods (mods that you previously unzipped into the OvGME Mods folder rather than left as .zip files). Without Developer mode, OMM only sees .zip files.
Restart OMM (or refresh the Library view). All your previous mods now appear in OMM's Library tab.

Watch for overlap. If any of your previous OvGME mods touched the same files as a VRS pack (e.g. another autostart for an airframe also covered by VRS_AutoStarts), only one can be installed at a time. Install your personal autostart or VRS_AutoStarts, not both.

Troubleshooting

The mod is installed in OMM but nothing changed in DCS. The internal folder layout of the mod is wrong - the folders inside the mod's top-level directory must match DCS's install folder layout (e.g. Mods/aircraft/FA-18C/Cockpit/Scripts/..., Scripts/...). Open a working mod and compare. (Note: if the mod is actually a livery or kneeboard, it belongs in Saved Games, not in OMM.)

OMM rejects the .zip as "unknown or wrong Mod Pack architecture". The filename and the top-level folder inside the zip don't match. VRS_AutoStarts.zip must contain a folder called exactly VRS_AutoStarts/ at its root. Don't rename downloaded zips.

DCS won't join the VRS server after installing a mod. VRS does not enforce strict integrity, but some mods (especially weapon/flight model edits) can still cause problems. Uninstall the mod, re-join, and ask in #questions on Discord before re-installing.

OMM says a file conflict / overlap occurred. Two installed mods both want to write the same file. The one installed last wins. Uninstall both, decide which one you want, install only that one.

Repository "Query" fails / 404. Double-check the Base URL is https://victorromeosierra.com (with https, no trailing slash) and the Name is the bare repo name without the .xml extension - OMM appends it itself, so writing VRSInstall.xml as the Name makes OMM fetch VRSInstall.xml.xml and 404. Confirm you can reach https://victorromeosierra.com/VRSInstall.xml (or https://victorromeosierra.com/VRSSavedGames.xml ) in a browser - if not, the repo may be temporarily offline.