l10n_de_01

Error:
Odoo Server Error

Traceback (most recent call last):
  File "/home/pro/dev/enterprise/account_reports/controllers/main.py", line 72, in get_report
    content = report_obj.get_csv(options)
  File "/home/pro/dev/enterprise/l10n_de_reports/models/datev_export_csv.py", line 120, in get_csv
    lines += line.encode('iso-8859-1')
TypeError: Can't convert 'bytes' object to str implicitly