There is an exclamation mark on the ipad information icon. What happened?

There is an exclamation mark on the information icon of ipad, because the sending of short message failed. You can click in and resend it to solve the problem.

iPadPro2020

iPadOS 14.4.2

Set 1.0

1, the mobile phone information has an exclamation point, which is caused by the failure to send the message. First, we turn on the phone and click the "Settings" system icon.

2. Then we click the "Information" option, as shown below.

3. Then we open the "iMessage" option on the right, close it and restart it.

But to clear the exclamation mark on the message, we need to turn off the Apple mobile phone.

5. Then turn on the Apple phone later. At this point, click the "Information" icon again.

6. Then send the unsent message.