In the provided dynamic block, what is the issue that causes it to result in an error?

In a dynamic block within Terraform, the purpose is to generate multiple nested blocks based on some collection. The use of the for_each argument is essential for iterating over that collection, which allows for the creation of multiple copies of the nested block with different configurations.

If the for_each argument is missing, Terraform lacks the necessary information to know how many instances of the block are required or what data to populate each instance with. This results in an error because the dynamic block is fundamentally designed to operate on collections; without for_each, the dynamic block cannot generate any content.

Therefore, the absence of for_each directly leads to the dynamic block being ineffective, resulting in an error message indicating that it cannot proceed with the block creation as intended. This highlights the critical role of iteration in defining dynamic content in Terraform configurations.