[General] 4 Separate small issues [please help][urgent]

[Camf△]

Your theme isn't updated going by your first post.

Authorization code mismatch fix
https://community.mybb.com/thread-218862...pid1309973

Modal fix
https://community.mybb.com/thread-213964...pid1288154

Attachments fix
Make sure these two templates are default
Templates > Your theme > Post Templates > post_attachments_new and post_attachments_attachment

When I use the align, or center function in a thread, it doesn't stay like that, it all reverts back to the right, once I post it 

This was fixed in the latest 1.8.21 update so update your forum also.
https://mybb.com/download

I updated myBB, it seemed to fix the issue with the centering. 
The modal fix and the attachment fix didn't work though :\