Could be a number of things. What is the exact error you are getting?
- Saved a Windows file over to a Mac...the File systems are not directly compatible. That would make the file "Read-only"...and would say so in the title bar of the window.
- You haven't created a record yet.
- You don't have access to modify the file.
- Logged in as a "Read-only" user
This can also happen if the file is opened from a CD instead of copying it to your hard drive and opening it there.
Also, check your permissions on the file. If the file is hosted by FileMaker Server, you have to UPLOAD it into FileMaker Server by using FileMaker Server's "upload" tool. You can't just drag-and-drop the file into the proper folder. FileMaker Server changes the permissions to what the right permissions need to be.