Error when trying to run modify-search.cmd

[saf-itpro]

Module: Create an Azure AI Search solution Section: Use the REST API to update the search solution of Explore and modify definitions of search components From step 2 of the above section, when I run ./modify-search command, I get the following error:

Updating the index...
{"error":{"code":"OperationNotAllowed","message":"Existing field 'language' cannot be changed.","details":[{"code":"CannotChangeExistingField","message":"Existing field 'language' cannot be changed."}]}}

A snapshot of the language element of my index.json file is as follows. As you can see here the language field is only retrievable and filterable.:

Question: What I may be missing here and how can we fix the issue?

[saf-itpro]

Problem SOLVED. It was my misunderstanding. Step 9 of Index the Document correctly states: Make the following changes to the index fields, leaving all other fields with their default settings. I mistook it as leaving all other checkboxes in the field to default. Since language field by default has Searchable box checked, I left it as checked - I should have unchecked it.