[Dylanblitz]

From the script reference it looks like you are trying to add permissions?
If you want to edit a permission group, there are two icon's you select from to edit/delete a groups permissions.

If you are trying to add a groups permissions, there is a bug that will be fixed in the next release. You select a group, say Registered Users, and click Add Permissions. When the next screen comes up, no mater what you selected on the previous, it will show the COPPA group. Just select the proper group again and it will work fine.

The error you are getting is a error when someone tries to add permissions for a group that already has permissions set on it.

On the second issue, it sounds like a permissions problem. The error happens when the image was uploaded but the server didn't let the script move the image. Verify that you have a folder forum/images/garage/attach that has permissions to allow the script to write to it. If you have it in another location verify that Relative Attachment Path variable is pointing to the right directory in the ACP.