Activate plugin: Uncaught Error: Class "YahnisElsts\PluginUpdateChecker\v5p3\Plugin\Ui" not found in /var/www/html/wp-content/plugins/seoai-client/plugin-update-checker-5.3/Puc/v5p3/Plugin/UpdateChecker.php:78

[Etyamor]

Plugin is conflicting with theme cause theme has class called ui inside.
As a result this code prevents to load the needed class for updates functionality (class_exists is not case sensitive):

namespace YahnisElsts\PluginUpdateChecker\v5p3\Plugin;

if ( !class_exists('Ui', false) ):
	/**
	 * Additional UI elements for plugins.
	 */
	class Ui {
...

Probably, better solution will be use condition in this way:

if ( !class_exists("YahnisElsts\\PluginUpdateChecker\\v5p3\\Plugin\\Ui", false) ):
	/**
	 * Additional UI elements for plugins.
	 */
	class Ui {
...

[YahnisElsts]

I believe this was already fixed in c1bf33e, I just haven't made a new release since then. Hopefully, I'll get around to that sometime this week.

[Etyamor]

Good to know. Thanks for a quick response. We're waiting for the new release from you 😄