rustdesk/rustdesk · error

Failed to get a drawing context

Error message

Failed to get a drawing context

What it means

GetDC(NULL) returned a NULL screen device context — the sentinel guard in DC::new. Without a screen DC none of the subsequent cursor drawing/bit-block-transfer operations can run; this essentially only happens under extreme GDI object exhaustion or a headless/broken session graphics stack.

Source

Thrown at src/platform/windows.rs:369

        }
        if bm.bmPlanes != 1 {
            bail!("Unsupported multi-plane cursor");
        }
        if bm.bmBitsPixel != 1 {
            bail!("Unsupported cursor mask format");
        }
        Ok(bm)
    }
}

struct DC(HDC);

impl DC {
    fn new() -> ResultType<Self> {
        unsafe {
            let dc = GetDC(0 as _);
            if dc.is_null() {
                bail!("Failed to get a drawing context");
            }
            Ok(Self(dc))
        }
    }
}

impl Drop for DC {
    fn drop(&mut self) {
        unsafe {
            if !self.0.is_null() {
                ReleaseDC(0 as _, self.0);
            }
        }
    }
}

struct CompatibleDC(HDC);

View on GitHub (pinned to 91c9fccbb0)

Solutions

1. Retry after releasing GDI resources — the process or session has likely exhausted its GDI handle quota
2. Check for leaking GetDC/SelectObject calls in the process (GDI leaks eventually cause exactly this)
3. Ensure the session has an active display device (not a detached services-only session)

When it happens

Trigger: Thrown at src/platform/windows.rs:369 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rustdesk/rustdesk@91c9fccbb0 (2026-09-10). Data as JSON: /api/errors/f2718fb8be1d5211. Report an issue: GitHub.