Welcome to Android Central! You may have installed an app that is causing system instability--either that, or the firmware is really glitchy (which wouldn't be too surprising in a budget/off-brand device).
See if you can boot into Safe Mode. While on, press and hold Power until the power menu appears. Then press and hold Power Off until you see the Safe Mode prompt, then tap OK. When it reboots into Safe Mode, all 3rd party apps will be prevented from starting. Now try uninstalling an app.