Error saving shader preset

[Dragu]

I found nothing on this, but perhaps I am also a little bit blind today.
I wanted to change in Retroarch (Hotkey+B) Quickmenu-Shaders sur SNES (Mario World). I can test it in the running game, but if I want to save, this bit.. tells me : "Error saving shader preset" What can be the problem ?

[Dragu]

In retroarchcustom.cfg is following line

video_shader = "/recalbox/share/shaders/custom/mysnesshader.gplsp"

But the folder /recalbox/share/shaders/ is not existing.

[Dragu]

I suppose because the chosed shader is in share_init, but not in the ES provided Set ?
Ok, I put this line in recalbox.conf, seems to work.

snes.shaders=/recalbox/share_init/shaders/shaders_glsl/scalehq/2xScaleHQ.glslp