Error generating review

Please advice on how to deal with the error:
The name column for the ‘xr3nl31’ choice list contains these duplicates: ‘_’, ‘__’. Duplicate names will be impossible to identify in analysis unless a previous value in a cascading select differentiates them. If this is intentional, you can set the allow_choice_duplicates setting to ‘yes’. Learn more:

Welcome to the community, @anastasialomova! Please be informed that when designing a survey project you will need to make the choices unique. If the choices are not unique, you will face the issue you are currently facing. For more details, please feel free to go through our post discussed previously:

Thank you Kal_Lam for your answer and recommendations.
Did i understand you right that the choices should be unique within one question or throughtout the whole survey?
I have tried to look for the duplicates within one question and could not find any.
May I kindly ask you to find at least one duplicate as an example so as I can move on with the corrections in the survey?
Thank you so much.

Please take a look at this screenshot:

The program finds duplicates within the choices/answers (for one question) marked in yellow, while I can’t.
Maybe duplicates should be avoided throughout the survey, and not only within the choices for one question?

Please advice. Thank you for your help.

Provide a unique name that could be like 1, 2, … etc. Then validate them with this online validator to see any remaining issues. The online validator should also be able to identify issues within your xlsform.