Clean Ubuntu 16.04 Server (with additionally thin XFCE Desk), Odoo 10 Community Edition without Demo data.

• Discussion

• Calendar

• Sales

• Purchase

• Warehouse

• Procurement

• Repairs

• Finance

• Website

• Website-Admin.

Added Data:

• ~ 60 Categories Website via XML import

• ~ 60 Categories Sales / Warehouse via XML import

• 5 Products, 4 with Time-Based units of Measure, 1 Standard.

• 3 QWeb modifications: report.external_layout_header & footer, sale.report_saleorder_document
  

Quotes, Sale Orders and Confirmations are printable without error, Printing invoice (draft or confirmed, no difference) brings:

Odoo Server ErrorTraceback (most recent call last):
File "/odoo/odoo-server/addons/report/controllers/main.py", line 108, in report_download    
  filename = safe_eval(report.print_report_name, {'object': obj, 'time': time})  
File "/odoo/odoo-server/odoo/tools/safe_eval.py", line 301, in safe_eval  
  return unsafe_eval(c, globals_dict, locals_dict)  File "", line 1, in <module>
ValueError: <type 'exceptions.NameError'>: "name 'Rechnung' is not defined" while evaluatingu'Rechnung'

Any Ideas?