This is will probably be my shortest blog post.
Last week while I was patching all the vCenters for VMSA-2021-0020.1 vulnerability one of the many vCenters display this error while checking for updates: Error in method invocation [Errno 2] No such file or directory: ‘/storage/core/software-update/updates/index’.
If you search for this error you will find many different solutions, but it depends on the root cause. In my case, this vCenter was in an isolated environment and it was not able to get to vmware.com default repository for updates. There were some ACLs that were blocking the access to vmware.com and once those were fixed, updates were available and everything worked fine.