Error export-fixtures with Custom Script

Hi, I’m working with ERPNext 13. I create a custom script, but when I do a export-fixtures return following error:

But, when a I change in file Custom Script → Client Script, work it!! And client_script.json file is created on fixtures folder.

This is an error or is an update in custom script??

PD: In my version of ERPNext, Custom Script no called like that, but they are called Client Script


provide your relevant content in your file, maybe you can change from Custom Script to Client Script in

Custom script has been named to client script in version 13.