I apologize you are experiencing this issue on your device. Do you have an external memory on your device/SD card? If so, try removing the SD card then recording.
I will also recommend to reset your camera settings to do this, follow these steps:
Open Camera> Press Gear icon at the top> Scroll to bottom> Reset Camera settings.
If issue persists after this try powering your device on Safe Mode. Safe Mode prevents any third party apps from running.
Restart> Hold Volume down buttom until power up> then try recording. If it's working during Safe Mode that indicated an existing application on your device is preventing the Camera from recording and you must uninstall third party applications.
To exit this mode, simply restart device again.
Hope this helps. Have a wonderful day!
Hello I am sorry to hear you are having difficulties with your phone. There are three solutions that I would give you to see if the video recording would work. The first one is to simply close the app itself that is where you click the three lines on the bottom of the screen and swipe up to officially close the app from running. Second solution if that does not work is to go to the camera and go to setting then go all the way to the bottom and click "Reset settings" it will give you a notification stating that camera settings will be reset and you want to go right ahead and click reset. Lastly if that does not work you can reset the phone by clicking on the volume down button and also the lock button at the same time. This will set a soft reset on the phone to make sure if any bugs are on the phone they can be cleared. All these solutions should fix the problem and if you have any concern Ill be here to answer any questions. Have a wonderful day.