As I know during readind iDoc was wrong base of unit measure - user change it on METERS (M) but ...
No valid unit of measurement can be determined for ISO code M
Message no. ME 851
Diagnosis
The IDoc cannot be processed because no unit of measurement can be determined for ISO code M.
Procedure
Contact your system administrator.
Procedure for System Administration
Check the ISO code of the currency in Customizing (general settings)and maintain if necessary.
what should I do or write there down... ?