This is a small compatibility fix required for all websites running WordPress 4.x.x – this update ensures not to call the blocks API (introduced with Gutenberg) where it does not exist due to an older WordPress version.
Do I have to update?
Gecko 18.104.22.168 is a minor release which only improves WordPress 4.x.x compatibility. If you are on WordPress 5.0.0+ there is no action required – if you want, you can skip 22.214.171.124 and wait for the next release.
Technical details of the issue
To register its own block types in the new WordPress editor, Gecko 126.96.36.199 is calling the register_block_type() function which was introduced in WordPress 5.0.0 along with Gutenberg and does not exist in WordPress 4.x.x.
To fix the problem, we have wrapped the code in if(function_exists()) block which ensures the call to non-existent function is not made on older versions of WordPress.