This occurred after an upgrade to EasyApache4 on the server:

Uncaught exception 'Whoops\Exception\ErrorException' with message 'Declaration of Concrete\Core\Workflow\Progress\PageProgress::add() should be compatible with Concrete\Core\Workflow\Progress\Progress::add($wpCategoryHandle, Concrete\Core\Workflow\Workflow $wf, Concrete\Core\Workflow\Request\Request $wr)' in /home/railfencebunch/public_html/concrete/src/Workflow/Progress/PageProgress.php:8 Stack trace: #0 /home/railfencebunch/public_html/concrete/src/Workflow/Progress/PageProgress.php(8): Whoops\Run->handleError(2048, 'Declaration of ...', '/home/railfence...', 8, Array) #1 /home/railfencebunch/public_html/concrete/vendor/symfony/class-loader/Symfony/Component/ClassLoader/Psr4ClassLoader.php(69): require('/home/railfence...') #2 [internal function]: Symfony\Component\ClassLoader\Psr4ClassLoader->loadClass('Concrete\\Core\\W...') #3 /home/railfencebunch/public_html/concrete/elements/page_controls_footer.php(12): spl_autoload_call('Concrete\\Core\\W...') #4 /home/railfencebunch/public_html/concrete/src/View/Vie