VMware – TPM 2.0 device detected but a connection cannot be established on DELL EMC PowerEdge

VMware – TPM 2.0 device detected but a connection cannot be established on DELL EMC PowerEdge

i just upgraded DELL EMC PowerEdge R740xd from vSphere 6.7 to 7.0.3 i got error message TPM 2.0 device detected but a connection cannot be established – how resolve it ? 

• TPM2 Algorithm Selection to SHA256
• Turn on Intel(R) TXT 
• Enable Secure Boot

This settings SHOULD NOT impact the ESXi installation, but there is a chance… that your machine will be unbootable ! 

Place the host into maitenance mode, reboot it and boot to System Setup > System BIOS. 

then go to the System Security

go to the TPM Advanced Settings

and enable SHA256 algorithm selection and go back to System Security

Intel(R) TXT – On 

and enable Secure Boot

save settings and reboot esx node, secure boot policy has been changed to enabled. 

Once it’s back in vCenter, you can go to the host and clear out the “Host TPM attestation alarm” alert by clicking Reset to Green, then exit Maintenance Mode.