This error is displayed from version 1.9.2 on and means that N and L are switched.

To prevent this please follow Etrel INCH electrical Installation Guide and sticker inside INCH:

3 phase connection:

• correct:
  

• wrong (L1 and N switched):
  
• wrong (L2 and N switched):
  
• wrong (L3 and N switched):
  

Please measure between each phase and ground. Results:

1 phase connection:

• correct:
  
•  wrong (switched L1 and N):
  
  

Please measure between phase and ground. Result: