Lost all default sounds after playing around with external plugins in OSX

All default sounds are lost. Even in old project files the default midi sounds do not play anymore. Also the out of the box midi instruments like piano or drums stay silent. I also tried to replace the default sound with the default EWQL Symphonic Orchestra but it didn't work as the EWQL does not work on new macs anymore. So maybe this destroyed some default setting? I can set the instruments to play the midi piano or the vst with a lot tweaking in the sound tab but the default sounds do not work anymore out of the box.  Is there a way to get back to the factory default? I did even reinstall the whole Synfire installation but things stay like the where before