As of last week our backups started failing due "Cannot complete login due to an incorrect user name or password" error with Acronis vmProtect 9.
when trying to login into the vcenter appliance with the vsphere client we get a "Cannont complet login due to an incorrect user name or password".
Password has not been changed and the vcenter appliance is not integrated into active directory.
We tried rebooting the server, it did not help. The ESXi version is 5.5.