Lists fail to render due to invalid key values

To ensure that your components render correctly, only set iteration keys to either a string or a number.

If a component throws one of these exception messages, make sure that its iteration key is set to a valid value.

• TypeError: Cannot read properties of undefined (reading '0')
• TypeError: Failed to execute 'removeChild' on 'Node': parameter 1 is not of type 'Node'

You can also validate your components’ iteration keys by running your application in debug mode. If a component that uses an iteration key throws any of these error messages in the DevTools console, verify that the key is a string or a number.

Error: [LWC error]: Invalid key value "[object Object]" in [object:vm LightningElement (1)]. Key must be a string or number.