Installed macro doesn't work

Hi, all. I’m very new to macros.

I wrote my first macros (language: IJ1 Macro) and it worked well when I run from macro editing window.
It also worked when I paste the codes in “Starup Macros” window.

When I saved it (.ijm file) in >Fiji app>scripts>“Plugins” folder (I created), it appears in Plugins drop down menu, however, it doesn’t work. The error message is following.

Undefined identifier in line 6:
+= File . separator ;

My question is why the macro which worked fine when I press “run” from macro editing window doesn’t work at all once I put it in the drop down menu? Same thing happened when I install the macro by >Plugins>Macros>Install…

I can use this macro but I’m getting tired of paste the code and run from the editing windows everytime I start Fiji.

What can I do?

Thanks in advance.