Encoding::UndefinedConversionError: "\xC3" from ASCII-8BIT to UTF-8

https://sentry.gitlap.com/gitlab/gitlabcom/issues/162058/

Encoding::UndefinedConversionError: "\xC3" from ASCII-8BIT to UTF-8
  json/common.rb:223:in `encode'
    state.generate(obj)
  json/common.rb:223:in `generate'
    state.generate(obj)
  json/common.rb:223:in `generate'
    state.generate(obj)
  json/common.rb:394:in `dump'
    result = generate(obj, opts)
  lograge/formatters/json.rb:6:in `call'
    ::JSON.dump(data)
...
(112 additional frame(s) were not displayed)

Encoding::UndefinedConversionError: "\xC3" from ASCII-8BIT to UTF-8