If you are having problems saving files such as treatment plans and/or dcmtk conversions it may be due to the state of POSIX file permissions for some of these folders. POSIX stands for Portable Operating System Interface for UniX, and is an IEEE standard designed to facilitate application portability. The buttons near the right side of this window allow you to view the current POSIX permissions and change the permissions of the associated folders. You must unlock physics to enable these buttons. For best compatibility, the POSIX file permissions for directories (folders) where PS saves files should be drwxrwxrwx which enables read, write and execute for all users. Clicking the permissions buttons cycles the folder's POSIX permissions between some standard configurations. Use the MacOS Finder Go to Folder and Get Info windows to create more customizable settings and to propagate those settings to enclosed folders.