After drag and drop the granular in the Product Explorer, in SEN2COR, In I/O parameters tab, please navigate and select this file, MTD_MSIL1C.xml
makw sure that you select the right product, the same was recently discussed here: Sentinel2 images correction error
It means, the process successful done.
But I can’t see any file called L2A.
It’s within the same folder where is L1C existed, output product is the output of L2A
if you select the “OutputProduct” in the ProductExplorer, you will see the path where it is stored in the top of the window
Maybe it was temporally named “OutputProduct” by SNAP while the actual filename is different.
Please use the search function in the upper left in STEP FORUM,
In order to run Sen2Cor 2.5.5 at 10m, Take a look at this post
call sen2cor 2.8 from the command line, first thing you need to add the sen2cor to your path, please have a look at the following post, How to add up sen2cor to the path, and retrieve the specific resolution.