the pb seems to reappear in high sierra. I did all the the cache deletion and so on I found on the garageband issue support site but it still be the same error msg.
the plugin is listed on AU section but when trying to use it, the error msg appears.
macOs version :10.13.1
Ilock version : the last automatically updated
UChannel version : 2.4.1
GB version : 10.2.0
Hey, please try restarting you computer. This was an issue on High Sierra that restarting seemed to fix. Please let me know if the problem persists.