ERROR: Could not open file : DISK_ERR

I solved the problem !!!! I didn't see that I swapped MISO and MOSI in my wiring... I saw it in the code that there must be something wrong. :)

The strange thing is that it worked with

var spi = new SPI();
spi.setup({mosi:B14,miso:B15,sck:B13});
E.connectSDCard(spi, A8);

but not with

SPI2.setup({mosi:B14,miso:B15,sck:B13});
E.connectSDCard(spi, A8);

Thank you so much for your patience and for your help Gordon!