We’ve just finished upgrading VMWare infrastructure from version 6.0 to version 6.5 and we’ve noticed that vSphere Web Client (Flash) is not working anymore with Firefox. After accessing vCenter IP Address, we select vSphere Web Client (Flash) as in the screenshot and we are getting the following error: “Error: Error #2134at com.vmware.flexutil.logging::StorageObjectWriter/initialize()at com.vmware.flexutil.logging::StorageObjectWriter$/getInstanceByName()at com.vmware.flexutil.logging::LocalStoreTarget/initialize() at com.vmware.flexutil.logging::LogManager$/addTarget()at com.vmware.flexutil.logging::LogManager$/addConfiguration()at com.vmware.flexutil.logging::LogManager$/onConfigLoaded()at ConfigurationLoader/onLoadSuccess()at flash.events::EventDispatcher/dispatchEvent()at flash.net::URLLoader/onComplete()” Our Firefox version is 70.0.1. The solution is pretty