Diagnosis
To guarantee the consistency of the InfoCube, you are not allowed to uselowercase letters and certain special characters in the specifiedInfoObject.
The BI Customizing Implementation Guide tells you how to maintainpermitted additional characters.

Procedure
In the specified record, check the corresponding field for:
capital/lowercase letters,
special characters that are not permitted,
the plausibilty of date and time entries, and
the correct observance of the ALPHA conversion routine.
Correct the field contents accordingly, and restart the load process.