If your vSphere system includes NSX-T Data Center, before you start an upgrade of your ESXi hosts, you must ensure that the NSX kernel module is part of the desired software specification or baseline that you use for the upgrade.

When you upgrade an ESXi host to 7.0 or later, all supported custom VIBs are migrated, regardless of whether the VIBs are included in the installer ISO. However, the NSX kernel module is not automatically migrated to the installer ISO image. Before you proceed to the upgrade operation, you must take one of the following actions: