Two days ago our AppCenter integration just stopped working. No changes in our config or scripts. We were using the Windows 4.1 orb, and I have upgraded to 4.1.1. This upgrade did not resolve the issue. The error from the AppCentere CLI login command is
Error writing to credential store, error code 0x520
specifically its an error from an internal call to creds.exe. This looks to me like a permissions issue on the windows machine.
Note that our bash based integration on other projects are still working fine.
Our existing delivery to AppCenter scripts use the appcenter-cli. Specifically we start the script with the appcenter login --token $Env:TOKEN command. This command adds the user’s credentials to the Windows Credential Manager via a tool called creds.exe
Sometime in the past week creds.exe has started failing and reporting the Error writing to credential store, error code 0x520 error. Reading a little deeper into the appcenter cli docs you find that if the environment variable APPCENTER_ACCESS_TOKEN is available then each appcenter cli command uses this token for authentication. The use of the APPCENTER_ACCESS_TOKEN removes the need to explicitly login, and also skips the step of adding credentials to the Credentials Manager.
So to resolve our issue, we removed the login command and made sure APPCENTER_ACCESS_TOKEN is in the environment. I’m not sure if there was an explicit change to the Windows executor to make the Credentials Manager unavailable to the user, or if we’ve just been getting lucky all this time.