PHP notice when a Toolset Maps Field is present in a Post (edit screen)

Symptoms

When Toolset Types, Maps and Views are active and an Address Field is added to a page or post, the following PHP Notice is thrown:

• Trying to access array offset on value of type null in .../toolset-blocks/vendor/toolset/common-es/php/Rest/Route/ShortcodeRender/WithMeta.php on line 74

This error repeats for several times until another, following notice is thrown:

• cannot modify header information - headers already sent by (output started at .../toolset-blocks/vendor/toolset/common-es/php/Rest/Route/ShortcodeRender/WithMeta.php:74) in .../wp-admin/admin-header.php on line 9

Workaround

This issue occurred with PHP 7.4 and was fixed with common code included in Blocks 1.3 release.