Hi ​@Kathy Constantine, 

Welcome to Box Community, and we’re glad help regarding your error moving a folder. 

Let’s start with the owner of the destination folder. Can you identify the owner, and ensure that this user has free space to house more contents. 

The folder owner could confirm his/her used storage via Box.com: 

• Login to Box.com and navigate to Account Settings> scroll down to Used Storage. 

Hope it helps, and for additional assistance please feel free to reply.