Before AppleScript will execute your code, the code must be compiled. You can compile your code separately, or else just try to run it (in which case, if it needs compiling, Script Debugger will automatically ask AppleScript to compile it before running it).

Any time your script is modified, it needs compiling. Script Debugger provides a clear indication of whether your script needs compiling. If you have checked the Editor preference “Show compiled state in gutter”, then a script that needs compiling has a striped “barberpole” pattern in the gutter. The illustration below shows a script that needs compiling.

To compile your code without running it:

• Choose Script > Compile. Alternatively, you can click the Compile button in the script window toolbar, or press the Enter key (different from the Return key).

If your script can’t be compiled because it isn’t valid AppleScript code, you’ll get an error message.

To force your script to recompile even if it hasn’t been altered, hold down the Option key and choose Script > Recompile (or click the Recompile button in the toolbar). This will also re-initialize persistent top-level entities to their base values.