Hello,
do you found a solution?
I have got the same problem. I'm using a 4.1.
As soon i call the function 'mySPI.begin();' my slave freezes.
If I use SPISlave_T4<&SPI1, SPI_8_BITS> mySPI; the slave is not freezing, but no communication will work. So I think the problem must be in this function...