Unknown error while adding new domain controller to existing domain

Recently I was building a lab domain and met an interesing issue. When I tried to add second domain controller (Windows 2012 R2 Standard Core) I've got following error: Install-ADDSDomainController : The operation failed because: An unknown error occurred while installing Active Directory Domain Services. "The parameter is incorrect." You must restart this computer to complete the operation. As it often happens with such errors no log entries were found, which would shed a light to the issue. While googling the error I found a discussion about similar issue. It was suggested the domain credentials are same as local logged on user. That wasn't my case but it lead me to different idea. Because it's lab environment and I'm pretty lazy I prefer to have empty passwords. So the domain admin account has the empty password. I set the password to non-empty and voila! New DC was added to the domain. Later I've set the password back to empty and it didn't seem to cause any problems on the already installed DC.