Warning: Unknown UCODE!!!
[...]
this dialog gets in the way and will not close therefore it's hard to test the emulator
Apart from that i heard crackling sound (expected due to poor performance in pure interpretrer) but the OpenGL window does not even seem to be updated, it remains filled with random artifacts, mainly from other windows
This dialog does not work. Some 2D games I've tried have had this problem (i.e. Puyo Puyo 4) and the dialog freezes the whole emulator. Your best bet is to use a different plugin once they become available.
On the flip side, the blank screen is not right. I'm going to guess the core is screwing up badly, or glN64 is not doing anything. Or both. How we tell is a new problem... How would we? anyone have ideas as to how?