Encoding error after upload mail blacklist


when I try to call the page admin/application_settings/general, I get the error message # 500 ### Encoding Error Page can't be loaded because of an encoding error. Last time I uploaded a .txt with mailadresses which I wanted to exclude from the registration. Is there a way to correct this?

I have found a solution using the API:
curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/application/settings?domain_blacklist_enabled=false&domain_blacklist="