My b2evolution Version: 4.1.x

I'm fairly sure this is simply because the LJ Crosspost hasn't been updated in a few versions, but I'd like to see if there's a way to fix this.

When I make or edit a post, I'm given this screen:

Warning: Missing argument 2 for load_class(), called in /MYSITEPATH/httpdocs/plugins/lj_crosspost_plugin/_lj_crosspost.plugin.php on line 595 and defined in /MYSITEPATH/httpdocs/inc/_core/_class5.funcs.php on line 84

Notice: Undefined variable: classname in /MYSITEPATH/httpdocs/inc/_core/_class5.funcs.php on line 87

Warning: Missing argument 2 for load_class(), called in /MYSITEPATH/httpdocs/plugins/lj_crosspost_plugin/_lj_crosspost.plugin.php on line 596 and defined in /MYSITEPATH/httpdocs/inc/_core/_class5.funcs.php on line 84

Notice: Undefined variable: classname in /MYSITEPATH/httpdocs/inc/_core/_class5.funcs.php on line 87

Warning: Cannot modify header information - headers already sent by (output started at /MYSITEPATH/httpdocs/inc/_core/_class5.funcs.php:84) in /MYSITEPATH/httpdocs/inc/_core/_template.funcs.php on line 216
An unexpected error has occurred!

If this error persists, please report it to the administrator.

Go back to home page
Additional information about this error:
Headers have already been sent. Cannot redirect.

If I click the redirect link, it takes me to the post, or wherever I'm supposed to go, and the crossposting does work just fine. I can live with the error page, but it would be helpful to get rid of it.