When casting, if some apps show a black screen or blurry image, it is usually because the phone system’s screen sharing protection restricts app video transmission, or the casting encoding is not properly compatible.

For Xiaomi, Huawei, and OPPO devices, follow the steps below to resolve the issue. Before operating, ensure the phone and the casting device (PC, TV, etc.) are connected to the same Wi-Fi network.

I. Basic Checks (Required Before Operation)

Before adjusting system settings, rule out basic issues to avoid ineffective operations:

a. Confirm app permissions:
Open the app that shows black screen/blurry image, then go to Settings → Apps → target app → Permissions.
Ensure Floating window, Display over other apps, and Storage permissions are enabled. Some video or game apps may additionally require Display over other apps permission.

b. Restart the casting link:
Turn off the phone casting function and the receiver on the casting device. Wait 10 seconds, then turn them on again.
Exit the currently casting app and clear it from background, reopen it, and start casting again.

c. Update software versions:
Update the phone system, 3uAirPlayer, and the problematic app to the latest versions. Older versions may have compatibility bugs.

II. Device-Specific Solutions (Core Operations)

Note: Developer Options are hidden by default on some Huawei and OPPO models and must be enabled first. Xiaomi devices can access Developer Options directly.

Device Type 1: Xiaomi Phones (including Redmi)

On Xiaomi devices, black screen or blur is usually caused by Screen Sharing Protection under Fraud Protection or Developer Options settings. Complete the two steps below:

Step 1: Disable Screen Sharing Protection in Fraud Protection

a. Open Settings, search for Fraud Protection in the top search bar, and enter the feature
(or navigate via Privacy & Security → Security → Fraud Protection).

b. On the Fraud Protection page, find Screen Sharing Protection
(some versions show Casting Protection), enter it and turn the switch off (blue → gray).

c. Return to the home screen, temporarily exit casting, wait 3 seconds, then start casting again to test.

Step 2: Disable Screen Protection Sharing in Developer Options

a. If Step 1 does not resolve the issue, open Settings → My device → All specs, and tap MIUI Version 7 times until You are now in Developer mode appears.

b. Return to Settings, go to Additional settings → Developer options
(some models under Privacy & Security).

c. Scroll down and find Disable screen protection sharing (keywords: screen protection/sharing), and turn it off.

d. Restart 3uAirPlayer, reconnect the device, and check whether the app display returns to normal.

Device Type 2: Huawei Phones (including Honor)

On Huawei devices, the issue mainly relates to screen protection settings in Developer Options. Enable Developer Options first:

Step 1: Enable Developer Options

a. Open Settings → About phone
(or System → About phone).

b. Find Build number (or HarmonyOS version) and tap it 7 times until You are now in Developer mode appears.

c. Return to Settings → System & updates → Developer options
(some models: More settings → Developer options).

Step 2: Disable Screen Protection Sharing

a. In Developer options, scroll to Debugging or Apps section and locate Disable screen protection sharing.

b. Toggle the switch off (some models require entering a subpage to disable).

c. If Screen sharing encoding optimization exists, try setting it to Compatibility mode.

d. Close all background apps, reopen the target app and 3uAirPlayer, then test casting again.

Device Type 3: OPPO Phones (including OnePlus, realme)

The logic is similar to Huawei. Focus on screen protection settings in Developer Options:

Step 1: Enable Developer Options

a. Open Settings → About device (or My device → About device).

b. Find Version number and tap it 7 times. If prompted, enter the lock screen password and continue until Developer mode enabled appears.

Step 2: Disable Screen Protection Sharing

a. Return to Settings → Additional settings → Developer options
(OnePlus path: System settings → Developer options).

b. Scroll to find Disable screen protection sharing
(some models show Screen sharing protection off) and turn it off.

c. If the casting image is blurry, find Casting resolution on the same page and set it to 1080P (device support required).

d. Reconnect the casting device, open the target app, and confirm the image is clear and no longer black.

III. Advanced Troubleshooting (If Above Methods Fail)

a. Disable power saving mode:
Power Saving / Super Power Saving on Xiaomi, Huawei, and OPPO may limit background operation and video quality.
Go to Settings → Battery and turn it off.

b. Switch casting protocol:
In 3uAirPlayer → Settings → Casting protocol, change from Miracast to AirPlay (device support required), or vice versa.

c. Check receiver device settings:

If casting to a PC, disable antivirus screen monitoring interception.

If casting to a TV, go to TV Settings → Display and set Resolution to 1080P or higher.

d. Clear casting app cache:
Go to Settings → Apps → Casting app → Storage → Clear cache (do not clear data).

Note: If certain sensitive apps (such as banking apps) still show a black screen after all steps, it is due to the app’s own privacy protection mechanism and cannot be bypassed via system settings. This is normal behavior.