Brown Marijuana leaves

A question from a fellow grower:

Would you help me identify why my plant’s leaves look like this

It could be numerous reasons, the most likely judging by the picture alone would be nutrient burn or nutrient lockout.

We need some more information please:

ILGM Support Tickett

What is the strain?
Indoor or Outdoor?
Size of space?
Soil or Hydro? Medium used?
PH?
Type of nutrients used? PPM levels?
Temperature?
Humidity %?
Light system/watts?
Vegetative Growth cycle or Bloom/Flower cycle?