Atmospheric correction for Sentinel 2

I am unable to correct the Sentinel-2 images from L1c to L2A using Sen2Cor plugin. It works well on some images while it doesn’t on other images with the error as shown in the picture. Can someone tell me the detailed process and probable errors involved during this process?

It looks like you renamed the Sentinel-2 product. You may not do it because Sen2Cor is searching for the correct product name string containg S2?_MSIL1C*.SAFE.