S2 Masks can't be used in Band Math in Graph Builder
Comming fron the forum: http://forum.step.esa.int/t/problems-with-selecting-masks-as-input-in-graph-builder/3494
As an example if we use opaque_clouds_10m as in the expression opaque_clouds_10m<1?0:1 in the Graph Builder it leads to the error message "Expression is invalid. Undefined symbol 'opaque_clouds_10m'".
Related to issue