If U# scripts with BehaviorSyncMode.Manual (or Continuous) and None set exist in the same object, an error will occur as shown in the attached image.

(When SC2 Input Manager is None and SC2 Seat Adjuster is Manual)

When combining Manual (or Continuous) and None, it would be nice if U# scripts behaved as synchronization objects without displaying any error-like messages.

In fact, this combination works as Manual Sync.

Looking at the archive logs below, it seems that this implementation is already in place, and the error message is just being displayed extra.