Please read this full announcement.

Tokens that were subject to vesting and have now had a portion become unlocked (August / September Build Acala and X amount that has unlocked from crowdloan) will need to claim these unlocked tokens before they can transfer. The process takes less than a minute and is simple.

Claims can be done through: https://apps.acala.network/ once the website is live by following this guide: https://guide.acalaapps.wiki/general/claiming-vested-aca

OR

by following the guide: https://wiki.acala.network/acala/get-started/acala-account/balance-type-and-vesting#claiming-vested-aca.

Once you claim these tokens, they can be transferred by following this guide: https://guide.acalaapps.wiki/general/bringing-tokens-to-karura/sending-and-receiving-aca

Any tokens that were not subject to vesting (April Build Acala and 20% Crowdloan) do not need to be claimed. Users can transfer by following this guide: https://guide.acalaapps.wiki/general/bringing-tokens-to-karura/sending-and-receiving-aca