Error message

Function ReflectionType::__toString() is deprecated

wp-content/plugins/fluentform/framework/Foundation/Container.php:215
FluentForm\F\F\Container->resolveClass()
wp-content/plugins/fluentform/framework/Foundation/Container.php:195
FluentForm\F\F\Container->resolveDependencies()
wp-content/plugins/fluentform/framework/Foundation/Container.php:179
FluentForm\F\F\Container->build()
wp-content/plugins/fluentform/framework/Foundation/Container.php:154
FluentForm\F\F\Container->resolve()
wp-content/plugins/fluentform/framework/Foundation/Container.php:137
FluentForm\F\F\Container->make()
wp-content/plugins/fluentform/framework/Foundation/HelpersTrait.php:47
FluentForm\F\F\Application->parseHandler()
wp-content/plugins/fluentform/framework/Foundation/HelpersTrait.php:244
FluentForm\F\F\Application->addAction()
wp-content/plugins/fluentform/app/Providers/MenuProvider.php:18
FluentForm\A\P\MenuProvider->booting()
wp-content/plugins/fluentform/framework/Foundation/Application.php:195
FluentForm\F\F\Application->bootstrapWith()
wp-content/plugins/fluentform/framework/Foundation/Application.php:178
FluentForm\F\F\Application->bootStrapApplicationProviders()
wp-content/plugins/fluentform/framework/Foundation/Application.php:92
FluentForm\F\F\Application->bootstrapApplication()
wp-content/plugins/fluentform/framework/Foundation/Application.php:78
FluentForm\F\F\Application->__construct()
wp-content/plugins/fluentform/framework/Foundation/Application.php:66
FluentForm\F\F\Application::run()
wp-content/plugins/fluentform/framework/Foundation/Bootstrap.php:201
FluentForm\F\F\Bootstrap::FluentForm\F\F\{closure}()
wp-includes/class-wp-hook.php:287
do_action('plugins_loaded')
wp-settings.php:420

Meanwhile, I am going to revert back to previous version.

I am on PHP 7.4