Bad arguments to length of list

Hey friends, I am making a messaging app like whatsapp but i am encountering a problem can you help me out. I have google and also use ai but no one has given a proper solution. Please help me out.
Chat Screen

Home Screen

Chat Screen Blocks

Home screen Blocks

Please help me out.

Post clear image of chat screen … getting message from me block

Here it is

Here are other blocks of chat screen

blocks (11)
blocks (12)

The first error message is telling you, that a length of list block got an empty string as value

Make sure, that value is not empty before starting the loop