[wp-testers] Warning: call_user_func_array()

[Stas Sușcov]

În data de Lu, 07-03-2011 la 03:29 -0600, Emil Uzelac a scris:
> Hey Guys,
> 
> Quick question. I am testing multisite on a fresh install, no upgrades. Site
> is located at example.com/dev/ so it is not a sub-domain. Now the Theme that
> I am working on works great on non-multisite, however when activated in
> multisite it gives me this error:
> 
> Warning: call_user_func_array() [function.call-user-func-array]: First
> argument is expected to be a valid callback, 'header_style' was given in
> /dev/wp-includes/plugin.php on line 395
> 
> This is http://pastebin.com/VFQV1ijB what I have in functions.php and
> http://pastebin.com/9exbQBy0 in header.php.
> 
> Once again this happens only if I activate the Theme in multisite.
> Of course everything works well if add_custom_image_header is removed from
> functions.php
> 
> I am sure that this looks like an issue from my end, but need to check with
> you first.
> 
> PS No plugins installed, not a single one.

`header_style` should be a valid callback as warning says. In common
words it should be a callable function/static method.

For a complete reference, check the codex page:
http://codex.wordpress.org/Function_Reference/add_custom_image_header#Examples