"Don't Panic" when changing snippet

I get

Don't Panic

The code snippet you are trying to save produced a fatal error on line 4:

Cannot redeclare some_function() (previously declared in C:\Program Files (x86)\Ampps\www\wp\wp-content\plugins\code-snippets\php\snippet-ops.php(383) : eval()'d code:2)
The previous version of the snippet is unchanged, and the rest of this site should be functioning normally as before.

Please use the back button in your browser to return to the previous page and try to fix the code error. If you prefer, you can close this page and discard the changes you just made. No changes will be made to this site.

when i try to save an exiting snippet.

Even with this code in the snippet

function some_function(){
  $test = '';
  return $test;
}

I can create and activate the snippet, just when i try to save again/change it i get that message.

https://wordpress.org/plugins/code-snippets/