1# Ability Subsystem Changelog 2 3## cl.ability.1 Behavior Change in startAbility for Full-screen and Split Window Modes 4 5**Access Level** 6 7Public API 8 9**Reason for Change** 10 11On 2-in-1 devices, when [supportWindowModes](../../../application-dev/reference/apis-ability-kit/js-apis-app-ability-startOptions.md) is configured with the values **fullscreen** and **split**, the window starts in a freeform window state, which is not as expected. 12 13**Impact of the Change** 14 15This change requires application adaptation. 16 17Before the change, when **supportWindowModes** is configured with the values **fullscreen** and **split** on a 2-in-1 devices, windows are launched in freeform window mode. 18 19After the change, when **supportWindowModes** is configured with the values **fullscreen** and **split** on a 2-in-1 devices, windows are launched in full-screen mode. 20 21 22**Start API Level** 23 24API 14 25 26**Change Since** 27 28OpenHarmony SDK 5.1.0.52 29 30**Key API/Component Changes** 31 32@ohos.app.ability.StartOptions.d.ts 33 34**System capability**: SystemCapability.Ability.AbilityRuntime.Core 35 36API: **supportWindowModes** 37 38**Adaptation Guide** 39 40In API version 15 or later, configure windows to launch in full-screen mode when **supportWindowModes** is configured with the values **fullscreen** and **split** on 2-in-1 devices. 41If the intention is to start in a freeform window state, add the **floating** configuration item to the existing **supportWindowModes** configuration. 42