An Install & Play game may fail to launch if Steam is closed too early, a required setup step is incomplete, ownership cannot be verified, or additional content is causing a conflict.
Start by quitting the current ONMO+ session and launching the game again from the ONMO+ catalog. During startup, keep Steam open and complete any instructions shown on screen.
Steam was closed during launch
Steam must remain open while it handles sign-in, licence verification, and game startup. If Steam was closed, quit the current ONMO+ session and start the game again. Steam cannot be reopened within the same session.
A game update has not finished
Wait for the update to download completely. If the game does not start automatically afterward, quit the session and relaunch it from the ONMO+ catalog.
A publisher launcher or account is required
Some Steam games also require a third-party launcher or publisher account. If prompted, install or open the required launcher and sign in to the relevant account.
If the launcher displays an error or does not complete the sign-in, quit the session and try launching the game again.
Steam cannot verify the game licence
A licence-verification error means that Steam or ONMO+ could not confirm access to the game. Check that:
The game is owned by the Steam account linked to ONMO+
You are signed in to the correct Steam account
The game is available for that account in your region
A recent purchase has had time to appear in your Steam library
If you linked the wrong account, unlink it from ONMO+ and connect the Steam account that owns the game.
Mods or Workshop content may be causing a conflict
Mods and Steam Workshop content can become incompatible after a game update or prevent a game from launching correctly. If possible, disable your mods and try launching the unmodified version of the game. If it launches successfully, re-enable the mods individually to identify the content causing the problem. For missing Workshop content, confirm that you are still subscribed to the item in Steam, wait for synchronization to finish, and relaunch the game.
The game includes DLC
ONMO+ currently supports only the base-game configuration. If your Steam account owns DLC for the game, the additional content may prevent the game from launching through ONMO+. There is currently no confirmed workaround for this limitation. See Why can’t I launch a Steam game that includes DLC? for more information.
The game still will not launch
If the problem continues after restarting the session and completing all required setup steps, contact Support through the live chat and include:
The name of the game
The error message shown, if any
The step at which the launch stops
Whether the issue happens every time you try