Dear user,
We recommend using the last available version of Sen2Cor 2.11.
When processing very old products, as suggested in point 14) of Sen2Cor FAQ, it is recommended to use product in SAFE compact format (since PB 02.04) that can be (re)downloaded, for example, from the following links:
https://scihub.copernicus.eu/dhus/#/home or Data and Information Access Services | Copernicus :
e.g. https://creodias.eu/
Please be aware of point 7) of Sen2Cor FAQ if you plan to install Sen2Cor version 2.11 on Linux recent distributions.
Cheers,