Light source keeps on suddenly not working

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What I expected to happen was...:
Describe what you thought should happen here

light sources should be working

What actually happened was...:
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Me and my friends keep getting this bug where the light source we have just suddenly stops working. Like torches and my lava fall lights and my farm keep on exploding and dying because I moved my farm underground with red stone lights and the lava fall but when this glitch happens everything just explodes and dies and I have to fix and replace all my light source every time this happens. 

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ... just suddenly happens
3. ...