A new error class message_too_large is raised when a serialized cross-session message exceeds the line cap. The error message states both the actual character count and the limit, and suggests putting bulk content in a file instead.
Cross-session message size now fails with a specific, actionable error
Oversized cross-session messages now fail with a specific error naming the size and the limit
You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
Cross-Session MessagingArea: what it touches
Bug FixesKind: in v2.1.235,
Bug FixesSection of the release