Debug an error message with a plan

I'm getting this error:
"""
{{error}}
"""

Context:
- Language/framework and version: {{stack}}
- What I was doing when it happened: {{action}}
- What I already tried: {{tried}}

Relevant code:
```
{{code}}
```

Give me:
1. The 3 most likely causes, ranked, with the reasoning for each
2. For each cause, a quick check that confirms or rules it out
3. The fix for the most likely cause
Don't guess at code you can't see; ask for it.