Activated

What happens if a Unit is unactivated, but I can’t activate them?

Community Errata, Rulebook Pg. 6. "...until all units have been activated" Replace with: "...until no player is able to activate a Unit"

When exactly is a Unit considered activated?

The moment it is chosen to activate. The rulebook mentions on page 13 that a Unit is given an Activation token at the end of the unit's Action (or forgo of) to mark that the activation has ended. There is no specific wording in regards when a Unit is considered “Activated”. Logically, a Unit is considered activated the moment it is chosen to activate.