SAP BW 7.4 upgrade error

Hi,

we are upgrading our BW environment from version 7.1 to 7.4.

Getting following activation error during shadow system create step.

Error:

Table Z40BW_CA_DTL_EXT is too long (>4030)

DDIC ACTIVATION ERRORS and RETUR NCODE in SAPA741EPU.

Diagnosis:

The sum of the field lengths of the table fields exceeds the allowed value.

Procedure:

Remove fields from the table or reduce length of the fields.

This table is existing table and have been using for a long time. Why do we need to edit this existing table? in BW 7.4 is there any limitation on field and table length?

Please advice.

Thanks

Sat