How to resolve error: "The post’s action links must be valid URLs"

Using the latest version of ShareKit to post URLs like so:

[SHKFacebook shareURL:[NSURL URLWithString:@"http://www.google.com"]];

is resulting in the following error message being displayed (in a web view):

Application response error
The post’s action links must be valid URLs. You开发者_运维技巧 can see this because you are one of the developers of the app.

What does this error message really mean, and (more importantly) how can it be fixed?

The problem occurs if 'SHKConfigMyAppURL' is not a valid URL.