I have EL CAPITAN mac pro 2013 with LACIE 4TB thunderbolt.
how can i do to fix it? any comand like FSCK.
i need to access my data.
thank you in advance
I would try to connect the LaCie drive to an other Mac or try it with an older OS X.
If the drive will initialize copy all data, and reformat the drive on El Capitan.