Hi,   I would suggest top open a Service Request to TAC. You will possibly end up with RMA.   Regards, Konstantin

Upgrade the ESXi hosts one by one first, make sure that cluster is healthy then and proceed with combined or split upgrade. Konstantin

Hi, Andy, From 2.1.1 you should be able to do direct upgrade to 3.0. Make sure to familiarize yourself with upgrade guidelines and prerequisites. Make sure to test upstream networking. Procedure described in the same document.   Konstantin