vCenter 9.1 patching pre-check fails with the error "Machine SSL Certificate Validation failed due to an internal error. Resolution: Replace the expired SSL certificate using Fixcerts."

Products

• VMware vCenter Server

Issue/Introduction

While updating vCenter to vCenter 9.1 pre-check fails with the error:

"Machine SSL Certificate Validation failed due to an internal error. Resolution: Replace the expired SSL certificate using Fixcerts."

In /var/log/vmware/applmgmt/update_microservice.log ,entries similar to the following can be found:

2026-04-22T06:00:11.453Z DEBUG applmgmt-update-microservice 4073370 [vc@4413 module=""certificate_precheck"" funcName=""checkCertificateExpiry"" lineNum=""82""] Machine SSL certificate loaded successfully.
2026-04-22T06:00:11.454Z DEBUG applmgmt-update-microservice 4073370 [vc@4413 module=""update_functions_target"" funcName=""fetchHostname"" lineNum=""195""] Fetching the hostname...
2026-04-22T06:00:11.455Z INFO applmgmt-update-microservice 4073370 [vc@4413 module=""update_functions_target"" funcName=""fetchHostname"" lineNum=""202""] hostname fetched successfully, hostname: vc.example.com
2026-04-22T06:00:11.455Z ERROR applmgmt-update-microservice 4073370 [vc@4413 module=""certificate_precheck"" funcName=""checkCertificateExpiry"" lineNum=""117""] An error occurred during SSL certificate verification: []"

Environment

VCF 9.1

Cause

Machine SSL Certificate Validation failed for SSL cert issued by Microsoft Azure RSA TLS.

Resolution

1 - Login to VC through SSH using root.

 

2 - Switch to Shell by running the command below:

 

shell

 

3 - Execute the command below:

 

find / -type f -name "certificate_precheck.py" -exec sed -i '/elif not isCertificateCNValid/,+5 s/^/# /' {} \;

 

4 - Proceed with the upgrade by selecting either "Stage" or "Stage and Install".