Mac OS X provides a great tool for watching the Import.log in order to see log entries generated by various FileMaker actions - especially when watching for errors on copy/paste actions. The application is called Console, and can be found within the Utilities folder.
To watch any given Import.log file simply follow these steps.
1. Open Console app in Applications > Utilities > Console
2. Choose File > Open... and navigate to the desired Import.log (or drag Import.log into the Open dialog)
3. Utilize the feature of Clear Display to see only the most recent log entries
You can also set the preferences to bring the Console window forward when the log is changed. See the pictures below.
Local file changes vs. Server
You can find the Import.log file within your Documents folder when you're making changes to server based copy of a FileMaker file.
Caption: Watching Import.log files makes it easy to see results of the most recent logged FileMaker actions.
Caption: Setting the Bring log window to front, send back after: check box can be a helpful reminder while developing.
Caption: Using the Clear Display, Insert Marker, Reload and Filter are quite helpful when troubleshooting.