why this error occurred ...?

You have put 2 sign up buttons

Merge the code

Ohh! you forgot to change the button name I think right?

  1. Use mouse Right click in the blocks page,
  2. Clock on download blocks as long then upload it
  3. You have error count in the screen. (See the yellow blocks, app will not perform with that red error which means multiple times you have dragged the block in to the project.
  4. Arrange the block by category, you can remove or modify the duplicate blocks.