Calendar sync error codes (mpbx-calendar-sync, mpbx-api-directory)

Raised by /api/v1/me/calendar-sync (W7-INT-03). Messages never contain a token or the provider's answer. Guide: Microsoft 365 and Google contacts and calendar presence.

Code	HTTP	Meaning	What to do
MPBX-CALSYNC-NOT-FOUND	404	You have no calendar connection.	Create one with PUT /me/calendar-sync.
MPBX-CALSYNC-PROVIDER-CHANGE	409	The provider of an existing connection cannot change.	DELETE /me/calendar-sync, then connect again.
MPBX-CALSYNC-PROVIDER-ANSWER	503	The provider did not answer, or its answer could not be read. The code is kept as last_error.	Try again later; reconnect if it persists.
MPBX-CALSYNC-TOKEN-UNREADABLE	500	The stored token cannot be opened (the data key changed).	Connect again with a new refresh token.