The user:url token ( i.e. author's url ) returns a fully qualified url.

I.e. http://127.0.0.1/user/admin

Now when you use that token you end up with http://127.0.0.1/127.0.0.1/user/admin.

The reason is in custom_breadcrumb.module on line 612 where that url gets forcefully crippled to http:/127.0.0.1/user/admin and from there on drupal sees it as a path and not a url.

If this call is a precaution to correct user input error it should be removed. If it is required for something else it should be tested for content and fq urls should not be touched.

I don't have enough insight into the module to actually provide a meaningful patch. I would simple remove that line. But that might have unwanted side effects I'm unaware of. But so far I haven't encountered any.