Conflict with Edit Author Slug

I’m trying to change the author’s slug to use firstname-lastname instead of the default one provided by WordPress. I came across the article on your site that says to use Edit Author Slug.

However, after activating the Edit Author Slug plugin as well as changing the author’s slug, I’m getting a Fatal Error that may or may not be an error from PublishPress.

Here is the error that I am getting:

Fatal error: Uncaught Error: Object of class WP_Error could not be converted to string in /Users/ynahpantig/code/site/wp/wp-includes/formatting.php:4203 Stack trace: #0 /Users/ynahpantig/code/site/wp/wp-includes/formatting.php(4203): str_replace(Array, Array, Object(WP_Error)) #1 /Users/ynahpantig/code/site/wp/wp-includes/class-wp-hook.php(287): ent2ncr(Object(WP_Error)) #2 /Users/ynahpantig/code/site/wp/wp-includes/plugin.php(206): WP_Hook->apply_filters(Object(WP_Error), Array) #3 /Users/ynahpantig/code/site/content/plugins/publishpress-authors/src/functions/template-tags.php(74): apply_filters('the_author', Object(WP_Error)) #4 /Users/ynahpantig/code/site/content/plugins/publishpress-authors/src/functions/template-tags.php(849): get_multiple_authors(0, true, true) #5 /Users/ynahpantig/code/site/wp/wp-includes/class-wp-hook.php(287): {closure}(Arra in /Users/ynahpantig/code/site/wp/wp-includes/formatting.php on line 4203

I have done the following tests with no luck:
– change the theme to a default WP theme
– deactivate all plugins except for PublishPress and Edit Author Slug
– remove any dashes in the URL

The only time that it is working ok with the Edit Author Slug plugin activated is if I leave it as the default author slug which makes me think that the error might be on their side, however if I just have the Edit Author Slug plugin activated and have changed the slug, the author page is working fine.