cannot download photos onto CD and Photo sometimes prevents me from logging out

Please read the following user tip and restate your question/problem in detail: Writing an Effective Apple Support Communities Question - Apple Community  

• Which versions of Catalina and Photos are you running?
• Is your library a managed or referenced library?

• Where is your library located?  If on an external HD how is that drive formatted and connected to your Mac?
• Do you have the iCloud Library enabled in the library?  If so, do you also have "Optimize Mac Storage" enabled.

How are you trying to get the photos onto the CD? Describe workflow in detail.

When you can't log out do you get a warning message? If so what is it?