Not that I would know of. However, even without vCenter up and running, your hosts and VMs will continue to work. Just the vCenter Server related features (vMotion, DRS, ...) will not be available.
Another question, what's the size of your environment and which vCenter Server features (e.g. vDS, DRS, ...) do you currently use. In smaller environments I usually prefer to setup a new vCenter Server and then connect the hosts to this new vCenter Server rather than to upgrading the existing one.
André