In case when you reset (Administration -> Diagnostics -> Caches -> versionedSettings) or somehow currupt cache of versioned setting — teamcity can fail of applying new versions of settings from repository.

In this case login to TeamCity server host. Navigate to <teamcity_data_dir>\system\caches\versionedSettings\ dir. And find which subdirectry contains settings of you project. Copy files fom .teamcity\ folder of you project repository to this dir to fix the issue

280 test 0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890

If you wan to add element in existing list - use nested joins:

ExternalBastionSecurityGroups - List<AWS::EC2::SecurityGroup::Id>
SecurityGroupsList            - List<AWS::EC2::SecurityGroup::Id>
Outputs.BastionSecurityGroup  - AWS::EC2::SecurityGroup::Id

SecurityGroupsList: !Join
  - ','
  - - !GetAtt [ securitygroups, Outputs.BastionSecurityGroup ]
    - !Join [ ',', !Ref ExternalBastionSecurityGroups ]

How to filter intalled on the host certificates by FriendlyName

@powershell "Get-ChildItem -Recurse Cert: | where { $_.FriendlyName -eq 'Starfield Class 2 Certification Authority' -or $_.FriendlyName -eq 'Starfield Services Root Certificate Authority - G2' -or $_.FriendlyName -eq 'Amazon Root CA 1'} | Format-Table -AutoSize | Out-String -Width 2000"