Why is there a layer of ice at the bottom of our freezer?

SOURCE: layer of ice forming on bottom inside of freezer - Samsung fridge freezer

might have the temperature too high .. buy a freezer thermometer and place in freezer

SOURCE: Whirlpool Freezer

your defrost drain is frozen remove the rear bottom panel on the freezer at the back insede the freezer and clear the defrost drain there will be a hole under the ice you just need to clear the drain not buy a new freezer

SOURCE: LG frost free fridge freezer GR-359sq

defrost drain is blocked - probably with ice. take the back panel off inside the freezer and melt the ice off with a hairdryer then follow up with hot water till it flows away freely. this takes some patience. if fault reoccurs then get back to me

SOURCE: Upright freezer door inside developing ice

The door seal is at fault. Regardless of the small tear it is not sealing well.
Take a dollar bill and close it in the door. Then pull on the bill to feel resistance.
You will find it pulls easily in some place. That is where your air leak is that is causing the condensation.
Do this about every 6 inches all the way around the seal.

SOURCE: kenmore freezer upright frost build up on door

first just take it out and clean that one carefully .And then set correctly and observe it,s working condition.then also it's not working means show it to ur near by worker those who repairs it