file permissions, error code -60002

Error -60002 is "The authorization parameter is invalid". An administrative user can already access any file in the system with the proper authentication from the Terminal, and there are already shared folders with similar permissions for this purpose. The permissions are set up the way they are to prevent unauthorized access - is there a particular reason you are fighting the system in this way?

Changing the group permissions will only work if you are a member of that group. As a system administrator you can change the group to something like "admin" or use Access Control Lists, but from your error message it appears that the authentication you are using is not correct. I am guessing that you are logged in as an administrator for the various machines, what are you using to try to change the permissions?

I am trying to install EZdrummer and get "Error" warnings...
I have gone to disc utility and have been able to verify the Disk, however the "Repair" option is greyed-out.

Toontrack (EZdrummer's creator) keeps telling me to "repair your system preferences" BUT I don't know how?!?!?!

Thanks in advance for your help

Repairing permissions is an important part of regular maintenance, and should always be carried out both before and after any software installation or update.

Go to Disk Utility (this is in your Utilities Folder in your Application folder) and click on the icon of your hard disk (not the one with all the numbers).

In First Aid, click on Repair Permissions.

This only takes a minute or two.

Thank you very much...that worked perfectly...should I hit the "Verify Disk Permissions" button?

Nope.

'Verify' is just a checkup to tell you if anything needs repairing.

'Repair' is exactly that, it repairs as it goes along.

Dominique,
You may be able to add your local machine account to the same group as each student.

For example:
Your account is called "The Admin". The shortname is "theadmin". The group is "theadmin" You (the owner) have, by default, read, write, and execute permissions to files within your user folder - /Users/theadmin.
The students account could be called "The Student". The shortname is "thestudent". The group is "thestudent". They (the owners) have, by default, read, write, and execute permissions to files within their user folder - /Users/thestudent.

You can both see into each others home folder and Public folders, but cannot dig any deeper due to file permissions.

Allowing file owners and group members the same permissions to items in their home folders is possible. You need to do some command line work.

Login as your admin account and open the terminal. At the prompt type:

sudo chmod -R 750 /Users/thestudent/Documents

Then hit enter. When it asks you for your password, type it in and hit enter. You have just given read and execute permissions to anyone in the "thestudent" group for the Documents folder in the students home folder. Now you need to add your account to the "thestudent" group.

At the command prompt, now type in:

sudo niutil -appendprop . /groups/thestudent users theadmin

Then hit enter. If you are prompted for your password again, type it in and hit enter.

At the command prompt, type:

sudo niutil -resync .

Then hit enter.
Quit the Terminal.
Reboot (for good measure).

You have just made your account a member of the same group as the student. Since that group has access to read and execute items in the Documents folder of their account, you can browse to it freely.

This information may prove useful to you, but if you are not comfortable with the command line or file permissions, do not attempt it. The login names, user names and group names I used in my examples were for demonstrative purposes only and those commands should not be copied and pasted verbatim into anyone's Terminal.app.