Casting another spell that requires concentration. You lose concentration on a spell if you cast another spell that requires concentration. You can't concentrate on two spells at once.
Taking damage. Whenever you take damage while you are concentrating on a spell, you must make a Constitution saving throw to maintain your concentration. The DC equals 10 or half the damage you take, whichever number is higher. If you take damage from multiple sources, such as an arrow and a dragon's breath, you make a separate saving throw for each source of damage.
Being incapacitated or killed. You lose concentration on a spell if you are incapacitated or if you die.
Simple question, does paralyze break concentration?
The Paralyzed condition includes the Incapacitated condition within it.
The Spellcasting rules in Chapter 10 provide that being Incapacitated breaks concentration:
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