I have just reproduced the problem. It occurs when the product is already loaded in snap. If the product is not open previously in SNAP and it is loaded in read module, the checkbox "Show masks" can be activated...
Omar Barrilero6 December 2016 at 09:15
Please, could you describe better your problem? I am not able to reproduce it: when I create a simple graph Read->BandMaths->Write with a L2A product, all scl and cloud masks are available (please, note that the checkbox "Show masks" in the expression editor should be selected).
I cannot use the SCL masks generated on L2A on BandMath module in Graph Builder, neither some L1C mask (e.g. opaque clouds).