I am trying to add a s/mime certificate to one of my identities. I have imported it using kleopatra but something went wrong (which I am still trying to narrow down). But meanwhile I see another problem connected to this:

The dialog, where I can select a s/mime certificate for signing or encryption, shows the certificate I have imported before. But once I select it, the icon in the 'Key ID' column gets a red cross indicating some kind of problem. But the dialog does not give any kind of hint what is actually wrong. 

It would be nice to have some kind of error message (maybe as a tooltip on the red cross of the icon, maybe displayed somewhere in the dialog).

Reproducible: Always

Steps to Reproduce:
1. Edit identity
2. Cryptography: change s/mime signing certificate or change s/mime encryption certificate
3. Select a bad certificate is the selection dialog

Actual Results:  
Red cross in the 'Key ID' column, no error message, 'Ok' button is disabled.

Expected Results:  
Give some kind of error message (displayed as tooltip or within the dialog window) which helps the user to track down the problem.

I am in two minds whether this a bug or a feature request. In its core, I suggest a kind of a new feature (some kind of error message in case of problems with one of the certificates). But on the other hand, the current behavior can be quite frustrating for the average user, because there is clearly something going wrong but there is no helpful information displayed. So there is clearly something missing and therefore I have select 'minor bug' for this.