can anyone help with this error message after reinstalling my library onto a new mac air m3? thanks,

Hey there, this has nothing to do with your subscription.

Synthmaster Player is not one of our products: https://www.kv331audio.com/synthmasterplayer.aspx

The error message is related to this: KOMPLETE KONTROL / MASCHINE Error: "*Product* could not be loaded, as it may not support Apple Silicon or VST2 to VST3 migration."

From what I see, VST3 is not one of the supported formats. Feel free to contact their support or use your DAW in Rosetta mode: How to Open Your DAW Using Rosetta