Conflict with FacetWP when no ‘title-tag’ theme support

When using FacetWP with AIOSEO and a theme that does not have ‘title-tag’ theme support, this results in JSON errors when using filtering with facets:

https://d.pr/i/m063H2

The cause is the output buffering to rewrite the title, here:

https://github.com/awesomemotive/all-in-one-seo-pack/blob/master/app/Common/Main/Head.php#L120-L122

This inserts HTML in FacetWP’s JSON response.

When a theme has title-tag support, this does not happen.

We have multiple users with this issue in our support. Currently the only solution is to instruct users to use:

add_theme_support( 'title-tag' );

Not sure if there is a solution, but maybe you can look into this.

Remco
FacetWP support team