JosefNemec/Playnite · error · Exception

Interactive session is already running

Error message

Interactive session is already running

What it means

Thrown by PowerShellRuntime.StartInteractiveSession when a previous interactive PowerShell session (interactiveRuntime) is still alive. Playnite supports only one attached interactive PS host at a time because it shares a single runspace ('PSInteractive') with the host process, so a second start is refused.

Solutions

1. Close the existing interactive PowerShell window (type 'exit' or close it) so the Exited handler disposes interactiveRuntime.
2. If the field is stuck non-null after a crash, restart Playnite to reset static state.
3. Before calling StartInteractiveSession again, confirm interactiveRuntime is null / IsDisposed.
4. Avoid issuing multiple Open Interactive Session commands in rapid succession.

Example fix

// before
PowerShellRuntime.StartInteractiveSession(vars);
PowerShellRuntime.StartInteractiveSession(vars); // throws

// after
PowerShellRuntime.StartInteractiveSession(vars);
// ... user works, closes the window, Exited handler nulls interactiveRuntime ...
PowerShellRuntime.StartInteractiveSession(vars); // ok

// No public getter is exposed; track liveness at the call site before starting:
// (reflective/field check is internal — callers should keep a single owner of StartInteractiveSession)
if (interactiveSessionStarted) { /* inform user a session is already running */ return; }
PowerShellRuntime.StartInteractiveSession(vars);
interactiveSessionStarted = true;

// Not externally type-guardable; guard at the command/UI layer:
bool CanStartInteractiveSession() => !interactiveSessionStarted;

try { PowerShellRuntime.StartInteractiveSession(vars); }
catch (Exception ex) when (ex.Message.Contains("already running")) { /* tell user to close the existing window */ }

When it happens

Trigger: StartInteractiveSession is invoked while interactiveRuntime != null (line 128). The previous process may still be running because its Exited handler only nulls interactiveRuntime after the powershell.exe process exits.

Common situations: User opened the interactive PowerShell debug session, then triggered Open Interactive Session again without closing the first. The previous powershell.exe window was closed via the X button but the process hadn't fully terminated and fired Exited yet. A crashed earlier session left interactiveRuntime non-null.

Related errors

• Cannot load script file, uknown format.
• e.Message
• LOC.ErrorPowerShellNotInstalled
• PowerShell 5.1 is not installed.
• Cannot execute script, no runtime given.

AI-assisted analysis of JosefNemec/Playnite@5911f4e964 (2026-08-13). Data as JSON: /api/errors/8bad338ceca06798. Report an issue: GitHub.

Appendix: source

Thrown at source/Playnite/Scripting/PowerShell/PowerShell.cs:130

            powershell = System.Management.Automation.PowerShell.Create(initialSessionState);
            runspace = powershell.Runspace;
            runspace.Name = runspaceName;
            SetVariable("ErrorActionPreference", "Stop");
            SetVariable("__logger", LogManager.GetLogger(runspaceName));
        }

        public void Dispose()
        {
            IsDisposed = true;
            runspace.Close();
            runspace.Dispose();
        }

        public static void StartInteractiveSession(Dictionary<string, object> variables = null)
        {
            if (interactiveRuntime != null)
            {
                throw new Exception("Interactive session is already running");
            }

            interactiveRuntime = new PowerShellRuntime("PSInteractive");
            variables?.ForEach(a => interactiveRuntime.SetVariable(a.Key, a.Value));
            interactiveProcess = new Process();
            interactiveProcess.StartInfo.FileName = @"c:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe";

            // This is really sad solution, but there's currently no way how to initialize these variables automatically, because:
            // - Enter-PSHostProcess is blocking so we can't pass any command after it
            // - We can't redirect stdin because then user wouldn't be able to interact witht the console
            // - Messages like WM_PASTE don't work on PowerShell console
            // - Passing CTLR-V and ENTER is not possible, because the only reliable method works globaly and can't be sent directly to window handle
            interactiveProcess.StartInfo.Arguments = $"-NoExit -Command \"" +
                $"Write-Host \"`n" +
                $"`tConnected to Playnite process.`n" +
                $"`tUse CTLR-V and ENTER to paste commands to initialize basic SDK variables.`n" +
                $"`tMore information at:`n" +
                $"`thttps://playnite.link/docs/master/tutorials/extensions/scriptingDebugging.html`n" +

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