Cubase 8 External FX problems


I’m working on a project incorporating a GA EQ-73. I’ve added it as an external fx within VST connections and assigned to it a send and return specific output (LYNX Aurora output, input 8).
It worked fine for a while and then i started getting weird responses on the Aurora on the specific output/input: bursts of signal like a loop feedback (although monitoring was off). Then i got strange symbols in the outputs inputs section of external FX. And now as a surprise i cannot choose an output or input within external FX and cant use the GA.

Any ideas? Please assist?