This might be because @alpert3925's pm box is full, or possibly yours. Double check that both of you have room/space for the pm. also make sure you are spelling the users name correctly.

 

In addition to what Pbrassat has said, Alpert may have set his conversation settings so that only people that he follows can start conversations with him, or have disabled the ability to receive conversations entirely from normal users.

 

It won't let me send one to him either. I've been meaning to file this. My inbox isn't full, so that's not the issue.

 

@alpert3925 @usernameofdeath I would firstly Recommend you to check your settings if you haven't already

 

I am able to start and recieve messages with other people just fine.

 

A forum administrator should possibly look into this.
@clou44

 

@usernameofdeath @alpert3925

The setting that both have you turned off is the top one shown here. 'Start conversations with you'. As both as you have it turned off, you will not be able to start a conversation with each other, however you will be able to start conversations with other people who have the setting set as it is below in the screenshot.

 

I've changed my settings to members only. Lets see if that solves it.