We are having problems with avatars not showing on posts, but some are showing up with wrong avatars.  The wrong avatars do not even belong to anyone in our group.
We are also having a hard time uploading pictures.

If I am answering this correctly, no topic in a forum is private from other members. You would have to make another forum, make it private and only allow those you want to see what is being posted.
Some administrators do this to have a place where only admins can discuss things about the forums.

Same here. It's been happening for a few days. Also.. forum is running slow again.

Same issues on my forum.

I posted a reply (on my site) and got the error too. My reply posted, but I hadn't realized it right away. Forum is also running slow.

I finally received a notice for my forum and another one.  Thank you!

Good! 
You're welcome.

It doesn't change anything for my forum.

The attatchment that USMC-Ace posted ( in the link), that is what is happening on my forum too.

You're welcome. If you have any problems with it, let me know and I will try to help.

In your admin panel is a "members" tab. Click on that and you will have a list of all members for your forum. It will show their emails, joined date and then status. Each member has the status options that you can change.Click on the arrow by status.. for the member you want to make a moderator and click on the moderator option. That should do it.