QQ sent a request to add friend information, but the other party did not receive it. What happened? How to solve it?

Check whether the network is stable, sometimes the network will be delayed. If you add too many friends that day, the system will restrict them, and you can wait until the next day to add them. Maybe the other party has set the add friend verification permission, which can be reset by the other party.

Network instability; Adding friends too many times, QQ can only send Friend Request 20 times a day; Your QQ belongs to the other party's blacklist, and the other party cannot add it. Maybe the other party has set "Refuse to add me as a friend" in the system settings.

Network instability; There are too many times to add friends, and QQ can only send out 20 Friend Request every day; Your QQ belongs to the blacklist of the other party, so you can't add the other party.

Because the network is unstable, the other party cannot receive the verification message; The other party can't receive the verification message because of too many friends, and QQ can only send Friend Request 20 times a day; The other party cannot receive the verification message because QQ belongs to the blacklist of the other party and cannot be added.

The network is unstable and there are too many friends. QQ can only send out 20 Friend Request every day; Your QQ belongs to the blacklist of the other party, so you can't add the other party.

It may be that the other party has set permissions, or it may be that the other party has received your friend application, and people have ignored the friend application.