why EGL_SURFACE_TYPE=EGL_PBUFFER_BIT + eglCreatePbufferSurface fail ?

Hello,

i don’t understand, when i create Surface = eglCreatePbufferSurface with attribute EGL_SURFACE_TYPE=EGL_PBUFFER_BIT then it’s fail :frowning:
but without the attribute EGL_SURFACE_TYPE=EGL_PBUFFER_BIT it’s work !

why ?