type 'List<dynamic>' is not a subtype of type 'List<Map<String, String>>'

This error message usually occurs when trying to assign a List object to a variable that expects a List<Map<String, String>> object.

Here's an example:

List<dynamic> dynamicList = [ {"name": "John", "age": 30}, {"name": "Mary", "age": 25} ];
List<Map<String, String>> stringMapList = dynamicList; // Error occurs here

In the above code, we have a List object called dynamicList that contains two Map objects with string keys and dynamic values. We then try to assign dynamicList to a variable called stringMapList, which expects a List<Map<String, String>> object.

However, since dynamicList is a List object, it can contain any type of object, including Maps with dynamic values. This means that it's not guaranteed that all the objects in dynamicList will have string values, which is what stringMapList expects.

To fix this error, we need to convert the dynamic objects in dynamicList to Map objects with string values. We can do this using the cast() method:

List<dynamic> dynamicList = [ {"name": "John", "age": 30}, {"name": "Mary", "age": 25} ];
List<Map<String, String>> stringMapList = dynamicList.cast<Map<String, String>>();

In the above code, we use the cast() method to convert dynamicList to a List<Map<String, String>> object. This ensures that all the objects in the list are Map objects with string keys and values, which is what stringMapList expects.