Updating the W3TC plugin to 2.7.6 causes the issue. We are running
PHP 8.0.30
WordPress 6.4.5
Solid backups 9.1.13
The issue is related to using AWS S3 for our CDN settings.
PHP Fatal error: Uncaught Error: Undefined constant GuzzleHttp\Client::VERSION in wp-content/plugins/backupbuddy/vendor/guzzlehttp/guzzle/src/functions.php:136
Stack trace:\n 0 wp-content/plugins/w3-total-cache/vendor/aws/aws-sdk-php/src/Handler/GuzzleV6/GuzzleHandler.php(40): GuzzleHttp\default_user_agent() 1 wp-content/plugins/w3-total-cache/vendor/aws/aws-sdk-php/src/WrappedHttpHandler.php(88): Aws\Handler\GuzzleV6\GuzzleHandler->__invoke() 2 wp-content/plugins/w3-total-cache/vendor/aws/aws-sdk-php/src/ClientSideMonitoring/AbstractMonitoringMiddleware.php(126): Aws\WrappedHttpHandler->__invoke()\n 3 wp-content/plugins/w3-total-cache/vendor/aws/aws-sdk-php/src/S3/PermanentRedirectMiddleware.php(43): Aws\ClientSideMonitoring\AbstractMonitoringMiddleware->__invoke()\n 4 /va…’, referer: wp-admin/upload.php
