Undefined reference to ml_epiano::sustain etc. (Daisy_seed)

[Koemetstippen]

Board Is Daisy seed.
Undefined reference ro ml_epiano::sustain and others.
I added the line ...ldflags= as found on youtube, but without succes.
I re-installed the ml_synttool repositery, but without succes

I hope it’ll work some day. I also tried the synth multi saw example and organ and they both worked on the daisy_seed,

Best regards,
Kurt