PHP Warning: Attempt to modify property of non-object

[sirschuyler]

Describe the bug
[20-May-2020 14:08:19 UTC] PHP Warning: Attempt to modify property of non-object in /wp-content/plugins/the-seo-framework-extension-manager/bootstrap/update.php on line 288
[20-May-2020 14:08:19 UTC] PHP Warning: Attempt to modify property of non-object in /wp-content/plugins/the-seo-framework-extension-manager/bootstrap/update.php on line 289
[20-May-2020 14:08:19 UTC] PHP Warning: Attempt to modify property of non-object in /wp-content/plugins/the-seo-framework-extension-manager/bootstrap/update.php on line 290

To Reproduce
Not sure… keeps showing up every so often in debug log

Expected behavior
No PHP warning

Screenshots

Additional context

• WordPress v5.4.1
• SEO Framework v4.0.7
• SEO Framework Extension Manager v2.3.1
  • Active Extensions: Incognito

[sybrew]

The site transient value must be an object, so I'm not sure where this would fail.

This is evident since WordPress always forwards an object. Source: [1], [2], [3].

Perhaps there's another plugin modifying the $value, whereafter Extension Manager receives a broken "object".

You can invoke this error instantly by going to /wp-admin/update-core.php, so deducting which non-WordPress.org plugin is the offending one should be easy 😄. Simply deactivate the plugins one by one until the error no longer spawns in your HTML header or error logs.