Group error tracker events by likely cause

Groups pasted error tracker events into at most six likely causes with counts, so I know which fix removes the most noise.

Task: Group the error events below into at most six groups that probably share a cause. Context: The events come from [application name] over [time period]. The application is written in [language and framework] and had a recent change to [recent deploy or change]. Rules: - Group by the failing line or message pattern, not by wording alone, and merge events that differ only in ids or timestamps. - Count the events per group using only the events I pasted. If the list looks cut off, say so and do not extrapolate. - Mark any event that fits no group as "unclear" rather than forcing it in. - Remove any token, email address or key you see from your answer and tell me to rotate any key that appears. Result: A table with the columns group, example message, count, probable cause and first thing to check, sorted by count. End with one sentence naming the group whose fix would remove the most events. Material: [paste the error events or a CSV export here]

Updated