If dontdisplaylastusername is turned on, loginui.exe keeps crashing with custom cred provider about windows-classic-samples

[oldnewthing]

You need to get a stack trace with symbols that match the DLL that you built. That would tell you that the crash is in CSampleProvider::GetCredentialAt with dwIndex=0, crashing at the _pCredential->QueryInterface(...) because _pCredential is null. I'll let you pick it up from there.

[oldnewthing]

Can you include a stack trace, or attach the files referenced in the event log?

[aabragan]

I reverted the lab to test a couple of different options but I will set it up again and send you the files as soon as I duplicate the issue, i.e. reinstall and turn on the setting. These will be for my credential provider, which is based on your sample.

[aabragan]

I uploaded the file as a .txt because .zip was not being accepted. rename the extension to .zip after downloading it. I am going to try to get you another crash dump from today when i can.

AppCrash.txt

[aabragan]

@oldnewthing
Thank you so much for the insight! I was able to get an updated crash dump from my latest build on Friday. Would you mind taking a look and letting me know what is going on?

ReportQueue for Cred Provider.txt

[aabragan]

@oldnewthing
I did add a null check on _pCredentialand that seems to have resolved the crashing of the Credential Provider. Should the V2 Sample be updated with a null check too? The GetCredentialAtmethod was not modified by me at all so I assume that anyone else using the sample will run into the same problem. The code in the Credential Initialize method would also need to change to handle a scenario where the provider was initialized but without an ICredentialProviderUser.

What are your thoughts?

[oldnewthing]

I forwarded this issue to the sample owner. Thanks for reporting it.

[aabragan]

@oldnewthing

Thanks for the assistance! I really appreciate it!