Front-end: PHP notice on a page

After activation (no settings were changed or saved) I have opened a page on my site, and added ?amp to get the AMP version. Above page content I see this notice:

Notice: AMP_Post_Template::verify_and_include was called incorrectly. Path validation for template (...\wp-content\plugins\accelerated-mobile-pages/includes/vendor/amp//templates/bread-crumbs.php) failed. Path cannot traverse and must be located in <code>WP_CONTENT_DIR</code>. Please see Debugging in WordPress for more information. (This message was added in version 0.1.) in ...\wp-includes\functions.php on line 4139

Also, note a double-slashes problem: /amp//templates/.

Developers, please, PLEASE use WP_Debug while developing your plugin.

• This topic was modified 7 years, 6 months ago by Slava Abakumov.