problems with SD card

Thanks for narrowing it down - 1v73 was the version with:

Allow filesystem to work on user-defined pins (fix #427)

With this commit

Looks to me like one thing that has changed is the SPI bit rate - it usually defaults to 100000, but it had been running the SD card at 1000000... Maybe you could try:

SPI2.setup({mosi:B15,miso:B14,sck:B13,baud:1000000});
E.connectSDCard(SPI2,D2);
console.log(require("fs").readdirSync());