CSV External system import is not working if uploaded file contains non-ASCII characters and default language is not English

Summary

• CSV External system import in spanish is not working if uploaded file contains non-ASCII characters.
• The "Next" button is grayed.

Steps to Reproduce

1. Go to Personal settings > change language to Spanish
2. Save changes
3. Go to "Importar sistema externo" (External System Import)
4. Click on "Importación a partir de Archivo CSV"
5. If the uploaded file contains non-ASCII characters the button "Next" is grayed
6. Warning that shows up: "El archivo CSV que ha proporcionado contiene caracteres fuera del conjunto ASCII. Asegúrese de fijar la codificación correctamente."
   • 

Note: This does not happen for English version:

• Warning that shows up: "The CSV file you uploaded contains non-ASCII characters. Make sure to set the right encoding."
• 

Expected Results

• The button "Next" shows up
• The import succeeds if the correct file encoding is chosen.
• The import succeeds if the wrong file encoding is chosen but warnings will show up in the logs.

Actual Results

• For spanish language:
  • A warning is thrown: "El archivo CSV que ha proporcionado contiene caracteres fuera del conjunto ASCII. Asegúrese de fijar la codificación correctamente."
  • The "Next" button is grayed.
  • It remains grayed also if changing the "File encoding" value.

• For English version:
  • A warning is thrown: "The CSV file you uploaded contains non-ASCII characters. Make sure to set the right encoding."
  • The "Next" button is not grayed.

Workaround

• Changing the language settings of the profile to "English" fixes the issue

Notes

• Please check First internal comment for extra details.