Can't save CC files on HD after clean install

I have MBP early 2010 + apple cinema display 2011. I experienced: slow performance and in the end MBP did not start up. I did a clean install El Capitan, reinstalled Adobe CC (latest update, 2017) and copied my backup files to the HD.

My problems:

1. I can open old CC files but I can't save them to HD. I can save them to my desktop and to external HD. The message I receive is: corrupt file, error code -5000, no authorisation for the HD.

2. I can't find my library anymore. If I want to remove preferences e.g. possibly to solve the problem.

3. Can't move  files to a folder or delete files, I have to give my password. I changed settings and have given all users read and write permission.

4. Can't save mail attachments to HD from mac mail.

Thank you very much for your help.

Carolien van Mulken