PM: We need you to fix a bug. One of our client's customers couldn't complete the form. Me: What error did they get? PM: I don't know, but it's very important we fix this. Me: Do we have steps to reproduce it? PM: No, can't you just fix it? Me: Did they retry the submission process? PM: I don't know. Me: Does it happen often? PM: Just this one customer as far as we know. Me: Well, do we at least know when it happened so I can find it in the logs? PM: Sometime last week. Look, this is really important to the client, can you just make this top priority? We want it fixed ASAP.
The "bug" has not been fixed because the devs still don't even know what the error is. We had another high-priority bug shortly before this because the client didn't understand that something wasn't allowed according to the access rules in the spec they (theoretically) helped write.