while creating customer account in magento 2 it shows “we can't save the customer”

Question

1 exception(s): Exception #0 (ReflectionException): Class Mageplaza\CustomerApproval\Model\Config\Source\AttributeOptions does not exist

Answer 1

This is most likely caused by removing the "Customer Approval" extension.

Looking at the source code of this extension it creates a customer entity attribute that implemented the mentioned class as a source model.

Check in database table eav_attribute for the attribute is_approved, and delete that row.