[solved]impossible to use SPDIF with cubase and roland quad capture Help

Hello, it s my first try with SPDIF, kemper, Roland Quad capture and Cubase.... and nothing work:

I plug my guitar into the input of the kemper
i plug the spdif cable from the kemper out to the spdif in of the quad capture.
I want to set the quad capture to spdif 44khz and it s impossible (just 96, clock is set to "external", ditgital in to auto)

in the kemper, output spdif guit studio, input normal

In cubase, vst connection, i set input to quad capture 3-4 (it s the spdif) and the output to 3-4 (spdif output)
new track (stereo) and nothing... no sound, nothing in, nothing out...
HELP!!!!!!

i shut down the PC, take a shower, restart all.. and it work !?
i don't understand why but it 's cool so ENJOY