You'll notice
Useful3 Signal2
File sync now tells you in plain words why it stopped or was unavailable.
What's wrong with this entry?
Anonymous. No account, no email.
What
The messages shown when file sync is unavailable or dies mid-session are now a straightforward table of codes to sentences, covering cases like not opted in, another writer holding the folder, the session already holding as many files as it may, a lost writer lock, and sync having ended earlier.
Evidence
the session holds as many synced files as it may
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Related
Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.