Getting an error in FM related to a Date Used to get the MAX Date. (COG10)

[gosoccer]

Hi everyone,
Could you pls help! Cognos 10/DB2 :)

I'm getting an ugly error when I changed our connection to DQM from Compatible in our Framework Model.
The Statement which is part of the filter of the Subject Query is as following,

[Physical View].[XXXX].[LS_DT]   = maximum(   [Physical View].[XXXX].[LS_DT]  for  [Physical View].[XXXX].[CSSE_ID]  )

The error is
XQE-DAT-0001 Data source adapter error: com.ibm.db2.jcc.am.SqlSyntaxErrorException: Invalid use of an aggregate function or OLAP function.. SQLCODE=-120, SQLSTATE=42903, DRIVER=4.19.26 - when processing query: SELECT

I think I need to use some sort of TO_DATE conversion perhaps but not sure.

Thanks a lot!