I re-installed the software BBS 3. It is running now. The delivery from China doesn't seem to be coming yet.
Now I also ordered the TL866 Plus Programmer, unfortunately I will have to wait for a few more weeks.
In the meantime I measured the voltage on the P301 port, from left to right 3.3V, 3.3V, 3.3V and GND would this port be suitable for Jtag?