Not able to send a PM

Includes forum rules and technical help.
Can someone let me know why I am getting the following message

Some users couldn't be added as they do not have permission to read private messages

Trying to send a message to someone who I have been chatting to for 2 years, very strange. Am I doing something wrong ?

Many thanks

Susan
Hi Maxwell_1602

You may not be able to send a private message if your 'Sent messages' folder is full or if the 'Inbox' of the person you are trying to contact is full. If your Sent messages folder is full, just delete a number of old private messages and you should then be able to send.

I hope this works but let us know if not.

Michael
I have now sorted this out with Maxwell :D