# Limitations

> This table lists the existing limitations for some of the Microsoft Teams activities and triggers.

This table lists the existing limitations for some of the Microsoft Teams activities and triggers.

| Activity or trigger | Limitation |
| --- | --- |
| Send Channel Message  Send Group Chat Message  Send Individual Chat Message  Reply to Channel Message | When posting a message, the message size limit is about 28kb. This limit includes all HTML elements such as text, images, links, tables, mentions, and so on. If the message size exceeds 28kb, the action fails with the following error: "Request Entity too large." |
| Invite Member to Channel | When you add a member to a team, you can set guest users as team owners. |
| Create Online Teams Meeting | When you create a Teams meeting and want to select a time zone, this action requires an Exchange Online mailbox. |
| Send Group Chat Message | When you create a chat, this action can handle a maximum of 20 users per chat, but doesn't support guest users. |
| Chat Message Posted  Chat Message Updated | When a new chat message is posted in any chat you participate in, the trigger supports only one user per flow. |
| Chat Message Posted  Chat Message Updated  Channel Message Posted  Channel Message Updated | Does not trigger for messages containing more than one word. |
| Chat Message Posted  Chat Message Updated  Channel Message Posted  Channel Message Updated | This data includes the message sender and the text that includes the time when the message was sent. |
| Channel Message Posted  Channel Message Updated | When a new message is posted to a channel in Teams, the trigger doesn't detect replies to an existing channel message. |