Troubleshooting

Start by turning on Additional Logging and read the log in your project's Saved/Logs folder. Most problems show up there as an EOS result code.

Common Result Codes

Result	Usual cause	Fix
EOS_NotConfigured	The plugin did not create an EOS platform, so every EOSCore function and async node fails right away with this result	Check that your configuration in Project Settings is complete and that its name matches Default Configuration Name (or -EOSConfig=). Look for GetEOSConfig() and PlatformCreate() errors in the log
EOS_InvalidUser	Connect login worked, but there is no EOS user for this external account yet	Call EOS_Connect_CreateUser with the ContinuanceToken from the login callback (once per account). The Login node does this for you
EOS_DuplicateNotAllowed from CreateDeviceId	A DeviceId already exists on this device	Not an error, continue with the login
EOS_AccessDenied, EOS_InvalidAuth	The client policy does not allow this action, or ClientId/ClientSecret are wrong	Check the client and its policy in the Developer Portal, see Client & Policy Settings
EOS_InvalidParameters	A required option is empty, often LocalUserId because the user is not logged in yet	Log in first, see Authentication
EOS_Auth_ScopeConsentRequired and other scope errors	The Scope Flags in Project Settings do not match the application permissions	Make them match, see Scope Consent

The plugin does not start

• "Failed to load EOS third party library": the EOS SDK binary next to the plugin could not be loaded. Check that Plugins/EOSCore/Source/ThirdParty/EOSLibrary/Bin exists in your build and that no other EOS SDK version is loaded.
• Warnings about EOSShared, OnlineSubsystemEOS, EOSVoiceChat or SocketSubsystemEOS in the editor log: one of the engine's EOS plugins is enabled. Disable them, or add [EOSSDK] bHasProjectBinary=true, see Installing the Plugin.
• Nothing happens at all: check that [OnlineSubsystem] DefaultPlatformService=EOSCore is set and that bEnabled is not false, see Configuring Online Subsystem.

Login problems

• The Epic Account login (Account Portal) does not open: the EOS overlay only works in a Standalone Game or a packaged game, not in PIE. See Epic Account.
• Login works but Online Subsystem functions say the player is not logged in: when you log in with the async nodes you have to update the player's UniqueNetId yourself, see Authentication.
• The player is logged out after about an hour: login tokens expire, see Refreshing Tokens.

Multiplayer problems

• Two instances on the same computer can't see each other: both use the same DeviceId. Use two different accounts, for example two DevTool credentials, see Testing Multiplayer.
• Can't join a session after leaving one: the old session was not destroyed, see Leaving a Session.
• Can't join your own dedicated server from the server browser: the server reports its external IP. Connect with open <local ip> on your local network, see Dedicated Server.

Player Data Storage

• ReadFile/WriteFile with a relative path fails: use an absolute path for the local file.
• Run one read and one write at a time. Starting a second transfer of the same kind before the first one has finished is not supported.