Universe with an UNV0023 error in a filter from BEx query's variable

Hi experts,

We have a BEx Query and we have created an Universe based on it.

Checking the integrity of the universe, we get the next error UNV0023 in a filter:

<OPTIONAL><FILTER KEY="[VUSTD01]"><CONDITION OPERATORCONDITION="Equal"><CONSTANT TECH_NAME="@Prompt('Estado','A','Estado\LovEstadoBase',mono,primary_key,,{'C':'[GPSTDOC].[C]'})"/></CONDITION></FILTER></OPTIONAL>

This filter comes from a BEx variable that is defined as:

-Ready for input

-Optional

-With a default value

Regards,

Javier