Data Transfers · Problems and messages
What does “That account needs signing in again — its access has expired” mean?
Short answer: The service's permission for Storage Studio expired or was withdrawn. Open More → Connect Accounts…, sign in to that account again, then retry. Nothing in the account was changed meanwhile.
The permission the service gave Storage Studio has expired or been withdrawn — for example after you changed your password, removed app access in the service's security settings, or after a long time unused. Storage Studio can't read or write that account until you sign in again.
Open More → Connect Accounts…, find the account, and sign in to it again. Then go back to the folder browser (or set the transfer up again) and carry on.
Nothing in the account was changed while access was missing.
Related: Cloud accounts · “Could not list folders”