I bought Synplant on my windows Pc a year ago. Now i have a MacBook and tried to register. it says in my Account that its activated on two pcs but when I open my DAW (FL) its still in trial mode. I already restarted and tried it a few times.

It's ok that it's activated on two PCs. Did you manage to get Synplant authenticated?

Please note that Synplant and Synplant 2 are two different licenses.

To download Synplant v1, use the 2022.11.25 installer found in the download archive