The 60-second fix
Open Android Settings, Apps, Permissions, and set Camera to Allow. Then force-stop the app and reopen it. This single sequence fixes the black screen in the overwhelming majority of cases our testers saw.
Check the permission properly
Do not trust the in-app prompt alone. On some Android skins the permission dialog can be dismissed without granting anything, and Umingle Android app will then show black video forever. The Settings path above is the source of truth: if it does not say Allow, it is not allowed.
Conflicting camera apps
Android hands the camera to one app at a time. If your stock camera, a video call app, or even a flashlight app with camera access is running in the background, the app gets nothing. Close everything camera-related from the recent apps screen and try again.
Force-stop and cache
Still black? Force-stop the app from the App info screen, clear its cache (not data), and relaunch. If the problem survives that, the general troubleshooting guide covers deeper causes like OS-level camera faults.
When it is hardware
Test the camera in your stock camera app. If it is black there too, the issue is hardware or a system fault, and no chat app can fix it. A reboot resolves a surprising number of these; a persistently dead camera needs a repair shop. The video chat guide will still be here when you are back.
