If you switch from backing up only locally to backing up either online or online and locally, there are several steps to perform to ensure your backups work properly and you maintain a restorable data set during the transition. Failure to do so may cause catalog errors that lead to data not backing up properly and restores failing. These instructions can also be used to transition from online-only or online and local backup sets to local-only.
The most reliable way to transition from local-only backups to online-only or online and local backups is to create a new computer account. This will allow you to keep the data from the old, local-only computer account around while you conduct backups with the new computer account. It also avoids any potential catalog issues associated with trying to move an existing computer account from local-only backup sets to online ones.
Create a new computer account under the same client account as the computer account we want to transition from.
Cleanly reinstall the software on the computer you want to back up and link it to the computer account made in (1).
Create the online-only or online and local backup sets you want and begin taking backups.
Once you have enough backups performed with the new computer account to meet your recovery point objective (RPO), you can then delete the old, local-only computer account and corresponding Local Vault folder.