Diagnosis
You attempted to set a field to 'not summarizable'. This field,however, is already used in queries and summation also takes place inthese queries using this field. This can be in the case both in basiclists as well as in statistics.

System Response
The required action could not be carried out.

Procedure
Delete the summation property for this field in the affected queries(you can determine the queries using the where-used list for a field).