Message type: E = Error
Message class:  AFWCH_FL - AFWCH: Filter Messages 
Message number: 044
Message text: A single filter already exists for this characteristic
The filter group already contains a single filter for this
characteristic.
You can only assign one single filter per characteristic to a filter
group (AND link).
You can create a new single filter for this characteristic, which
contains all the values you require.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message AFWCH_FL044, which states "A single filter already exists for this characteristic," typically occurs in the context of SAP BW (Business Warehouse) or SAP HANA when you are trying to apply a filter to a characteristic in a query or report, but a filter for that characteristic has already been defined.
Cause: Existing Filter: The primary cause of this error is that a filter for the specified characteristic has already been applied in the query or report. SAP does not allow multiple filters for the same characteristic to avoid ambiguity in data retrieval. Query Design: This can happen during the design of a query in the BEx Query Designer or when using a report that is based on a query that already has a filter set for that characteristic.
Solution: Check Existing Filters: Review the filters that are currently applied to the query. You can do this in the BEx Query Designer
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
AFWCH_FL043 No suitable filters exist for this analysis structure
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
AFWCH_FL042 Error while creating objects for the ALV grid
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
AFWCH_FL045 Filter category & is NOT supported by FO selection
What causes this issue?  Single filters are <ZH>currently</> not required for the parameters and characteristic hierarchy. The correspondi...
AFWCH_FL046 No test entries exist for filter &
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.