Because on two groups of identical blocks one works and one doesn't

Translated with Google.
Hello, I’m doing a small photo gallery, I don’t understand why the blocks of the first section work while those of the second don’t.

Your blocks have no protection against incorrect data or handling erroneous situations, and you ask why it doesn’t work?

Display the contents of all the blocks that data passes through on the screen, and you will see an error.

You shouldn’t have 2 “screen starts” with different contents… not sure how code compiler will execute these instructions when screen starts.

2 Likes