Error: TypeError: Already read

I have created a drop down list with

          class="uk-select" id="form-ReadSecurity"
          @onChange={{this.selectReadSecurity}} as |option|>

and whenever I change the option and try to save using the save button I am getting an error ‘Error: TypeError: Already read’ I have other drop down list too which is not created using but it is working fine.

Can anyone help me understand the issue. Thanks in advance!

I have a similar question to @NullVoxPopuli’s comment on your StackOverflow post: Can you show us what the contents of the functions backing this component?

I have only seen the error TypeError: Already read when working with a promise returned from fetch and calling one of the body parsing functions twice (for example: javascript - What does this error mean — Uncaught TypeError: Already read? - Stack Overflow).