Issue
An older experience relies on Legacy Chat modules or a custom chat fork and chat behavior no longer matches current platform support.
Cause
Roblox retired support for the legacy system and directed creators to TextChatService.
Fix
Set the experience to TextChatService, replace legacy module hooks with TextChannel and TextChatCommand behavior, and move message styling into OnIncomingMessage. Test system messages, team channels, whispers, moderation, and console behavior separately.
Verify
Publish to a private test place and join with two accounts. Confirm normal chat, commands, filtering, blocking, and reconnects.
Official Roblox migration announcement
#1
Original Heliotrope guidance with authoritative Roblox sources.