Under very rare circumstances, a mixture of PHP files can exist in Studio Server. The most likely scenario of this occurring is during an upgrade of Studio Server. As part of the upgrade process therefore, accessing the Health Check page automatically clears the Zend OPcache folder so this scenario should automatically resolve itself.
Should the need arise though, the Zend OPcache can also be cleared manually.
Step 1. In Studio Server, click Advanced in the Maintenance menu or on the Home page. A page with all advanced Maintenance features appears.
Step 2. Click Clear Zend OPcache.
The cache of Zend OPcache is cleared.